d: Merge upstream dmd eb7bee331, druntime 27834edb, phobos ac296f80c.

D front-end changes:

    - Import dmd v2.100.0-beta.1.
    - Print deprecation messages for scope violations unless
      `-frevert=dip1000' is used.
    - Fixed a missed case of switch case fallthrough not being caught by
      the compiler.

D runtime changes:

    - Import druntime v2.100.0-beta.1.

Phobos changes:

    - Import phobos v2.100.0-beta.1.

gcc/d/ChangeLog:

	* dmd/MERGE: Merge upstream dmd eb7bee331.
	* dmd/VERSION: Update version to v2.100.0-beta.1.
	* d-lang.cc (d_handle_option): Handle OPT_frevert_dip1000.
	* lang.opt (frevert=dip1000): New option.

libphobos/ChangeLog:

	* libdruntime/MERGE: Merge upstream druntime 27834edb.
	* src/MERGE: Merge upstream phobos ac296f80c.
	* src/Makefile.am (PHOBOS_DSOURCES): Add std/int128.d.
	* src/Makefile.in: Regenerate.

11 files changed, 455 insertions, 64 deletions

diff --git a/libphobos/libdruntime/MERGE b/libphobos/libdruntime/MERGE
index 5e2566c9ceb..e08d9cdc0fd 100644
--- a/libphobos/libdruntime/MERGE
+++ b/libphobos/libdruntime/MERGE
@@ -1,4 +1,4 @@
-9ba9a6ae2b8f6811cb85107cb56701df04f36ac6
+27834edb5e1613e3abd43e09880c36d9fc961938
 
 The first line of this file holds the git revision number of the last
 merge done from the dlang/druntime repository.
diff --git a/libphobos/libdruntime/core/exception.d b/libphobos/libdruntime/core/exception.d
index a6928660773..81aa43b27d0 100644
--- a/libphobos/libdruntime/core/exception.d
+++ b/libphobos/libdruntime/core/exception.d
@@ -19,29 +19,6 @@ void __switch_errorT()(string file = __FILE__, size_t line = __LINE__) @trusted
         assert(0, "No appropriate switch clause found");
 }
 
-version (D_BetterC)
-{
-    // When compiling with -betterC we use template functions so if they are
-    // used the bodies are copied into the user's program so there is no need
-    // for the D runtime during linking.
-
-    // In the future we might want to convert all functions in this module to
-    // templates even for ordinary builds instead of providing them as an
-    // extern(C) library.
-
-    void onOutOfMemoryError()(void* pretend_sideffect = null) @nogc nothrow pure @trusted
-    {
-        assert(0, "Memory allocation failed");
-    }
-    alias onOutOfMemoryErrorNoGC = onOutOfMemoryError;
-
-    void onInvalidMemoryOperationError()(void* pretend_sideffect = null) @nogc nothrow pure @trusted
-    {
-        assert(0, "Invalid memory operation");
-    }
-}
-else:
-
 /**
  * Thrown on a range error.
  */
@@ -218,17 +195,17 @@ private void rangeMsgPut(ref char[] r, scope const(char)[] e) @nogc nothrow pure
  */
 class AssertError : Error
 {
-    @safe pure nothrow this( string file, size_t line )
+    @safe pure nothrow @nogc this( string file, size_t line )
     {
         this(cast(Throwable)null, file, line);
     }
 
-    @safe pure nothrow this( Throwable next, string file = __FILE__, size_t line = __LINE__ )
+    @safe pure nothrow @nogc this( Throwable next, string file = __FILE__, size_t line = __LINE__ )
     {
         this( "Assertion failure", file, line, next);
     }
 
-    @safe pure nothrow this( string msg, string file = __FILE__, size_t line = __LINE__, Throwable next = null )
+    @safe pure nothrow @nogc this( string msg, string file = __FILE__, size_t line = __LINE__, Throwable next = null )
     {
         super( msg, file, line, next );
     }
@@ -692,26 +669,49 @@ extern (C) void onFinalizeError( TypeInfo info, Throwable e, string file = __FIL
     throw staticError!FinalizeError(info, e, file, line);
 }
 
-/**
- * A callback for out of memory errors in D.  An $(LREF OutOfMemoryError) will be
- * thrown.
- *
- * Throws:
- *  $(LREF OutOfMemoryError).
- */
-extern (C) void onOutOfMemoryError(void* pretend_sideffect = null) @trusted pure nothrow @nogc /* dmd @@@BUG11461@@@ */
+version (D_BetterC)
 {
-    // NOTE: Since an out of memory condition exists, no allocation must occur
-    //       while generating this object.
-    throw staticError!OutOfMemoryError();
-}
+    // When compiling with -betterC we use template functions so if they are
+    // used the bodies are copied into the user's program so there is no need
+    // for the D runtime during linking.
 
-extern (C) void onOutOfMemoryErrorNoGC() @trusted nothrow @nogc
-{
-    // suppress stacktrace until they are @nogc
-    throw staticError!OutOfMemoryError(false);
+    // In the future we might want to convert all functions in this module to
+    // templates even for ordinary builds instead of providing them as an
+    // extern(C) library.
+
+    void onOutOfMemoryError()(void* pretend_sideffect = null) @nogc nothrow pure @trusted
+    {
+        assert(0, "Memory allocation failed");
+    }
+    alias onOutOfMemoryErrorNoGC = onOutOfMemoryError;
+
+    void onInvalidMemoryOperationError()(void* pretend_sideffect = null) @nogc nothrow pure @trusted
+    {
+        assert(0, "Invalid memory operation");
+    }
 }
+else
+{
+    /**
+     * A callback for out of memory errors in D.  An $(LREF OutOfMemoryError) will be
+     * thrown.
+     *
+     * Throws:
+     *  $(LREF OutOfMemoryError).
+     */
+    extern (C) void onOutOfMemoryError(void* pretend_sideffect = null) @trusted pure nothrow @nogc /* dmd @@@BUG11461@@@ */
+    {
+        // NOTE: Since an out of memory condition exists, no allocation must occur
+        //       while generating this object.
+        throw staticError!OutOfMemoryError();
+    }
 
+    extern (C) void onOutOfMemoryErrorNoGC() @trusted nothrow @nogc
+    {
+        // suppress stacktrace until they are @nogc
+        throw staticError!OutOfMemoryError(false);
+    }
+}
 
 /**
  * A callback for invalid memory operations in D.  An
diff --git a/libphobos/libdruntime/object.d b/libphobos/libdruntime/object.d
index a15616c6e0f..e58afa2f985 100644
--- a/libphobos/libdruntime/object.d
+++ b/libphobos/libdruntime/object.d
@@ -2830,8 +2830,8 @@ extern (C)
 
     private struct AA { void* impl; }
     // size_t _aaLen(in AA aa) pure nothrow @nogc;
-    private void* _aaGetY(AA* paa, const TypeInfo_AssociativeArray ti, const size_t valsz, const scope void* pkey) pure nothrow;
-    private void* _aaGetX(AA* paa, const TypeInfo_AssociativeArray ti, const size_t valsz, const scope void* pkey, out bool found) pure nothrow;
+    private void* _aaGetY(scope AA* paa, const TypeInfo_AssociativeArray ti, const size_t valsz, const scope void* pkey) pure nothrow;
+    private void* _aaGetX(scope AA* paa, const TypeInfo_AssociativeArray ti, const size_t valsz, const scope void* pkey, out bool found) pure nothrow;
     // inout(void)* _aaGetRvalueX(inout AA aa, in TypeInfo keyti, in size_t valsz, in void* pkey);
     inout(void[]) _aaValues(inout AA aa, const size_t keysz, const size_t valsz, const TypeInfo tiValueArray) pure nothrow;
     inout(void[]) _aaKeys(inout AA aa, const size_t keysz, const TypeInfo tiKeyArray) pure nothrow;
diff --git a/libphobos/libdruntime/rt/aaA.d b/libphobos/libdruntime/rt/aaA.d
index 0c38622a879..ab93f191634 100644
--- a/libphobos/libdruntime/rt/aaA.d
+++ b/libphobos/libdruntime/rt/aaA.d
@@ -504,7 +504,7 @@ extern (C) size_t _aaLen(scope const AA aa) pure nothrow @nogc
  *      If key was not in the aa, a mutable pointer to newly inserted value which
  *      is set to all zeros
  */
-extern (C) void* _aaGetY(AA* paa, const TypeInfo_AssociativeArray ti,
+extern (C) void* _aaGetY(scope AA* paa, const TypeInfo_AssociativeArray ti,
     const size_t valsz, scope const void* pkey)
 {
     bool found;
@@ -525,7 +525,7 @@ extern (C) void* _aaGetY(AA* paa, const TypeInfo_AssociativeArray ti,
  *      If key was not in the aa, a mutable pointer to newly inserted value which
  *      is set to all zeros
  */
-extern (C) void* _aaGetX(AA* paa, const TypeInfo_AssociativeArray ti,
+extern (C) void* _aaGetX(scope AA* paa, const TypeInfo_AssociativeArray ti,
     const size_t valsz, scope const void* pkey, out bool found)
 {
     // lazily alloc implementation
diff --git a/libphobos/src/MERGE b/libphobos/src/MERGE
index 0feb0b01ef5..3218ace50a0 100644
--- a/libphobos/src/MERGE
+++ b/libphobos/src/MERGE
@@ -1,4 +1,4 @@
-c0cc5e917db105301dd1199b4b3c854626526407
+ac296f80cda437483b743f953dc69cb1271c82df
 
 The first line of this file holds the git revision number of the last
 merge done from the dlang/phobos repository.
diff --git a/libphobos/src/Makefile.am b/libphobos/src/Makefile.am
index 75f83974e99..da7a2004ff8 100644
--- a/libphobos/src/Makefile.am
+++ b/libphobos/src/Makefile.am
@@ -130,7 +130,7 @@ PHOBOS_DSOURCES = etc/c/curl.d etc/c/zlib.d std/algorithm/comparison.d \
 	std/experimental/typecons.d std/file.d std/format/internal/floats.d \
 	std/format/internal/read.d std/format/internal/write.d \
 	std/format/package.d std/format/read.d std/format/spec.d \
-	std/format/write.d std/functional.d std/getopt.d \
+	std/format/write.d std/functional.d std/getopt.d std/int128.d \
 	std/internal/attributes.d std/internal/cstring.d \
 	std/internal/math/biguintcore.d std/internal/math/biguintnoasm.d \
 	std/internal/math/errorfunction.d std/internal/math/gammafunction.d \
diff --git a/libphobos/src/Makefile.in b/libphobos/src/Makefile.in
index f2395e2caf7..6f58fee01ac 100644
--- a/libphobos/src/Makefile.in
+++ b/libphobos/src/Makefile.in
@@ -228,6 +228,7 @@ am__dirstamp = $(am__leading_dot)dirstamp
 @ENABLE_LIBDRUNTIME_ONLY_FALSE@	std/format/spec.lo \
 @ENABLE_LIBDRUNTIME_ONLY_FALSE@	std/format/write.lo \
 @ENABLE_LIBDRUNTIME_ONLY_FALSE@	std/functional.lo std/getopt.lo \
+@ENABLE_LIBDRUNTIME_ONLY_FALSE@	std/int128.lo \
 @ENABLE_LIBDRUNTIME_ONLY_FALSE@	std/internal/attributes.lo \
 @ENABLE_LIBDRUNTIME_ONLY_FALSE@	std/internal/cstring.lo \
 @ENABLE_LIBDRUNTIME_ONLY_FALSE@	std/internal/math/biguintcore.lo \
@@ -591,7 +592,7 @@ libgphobos_la_LINK = $(LIBTOOL) --tag=D $(libgphobos_la_LIBTOOLFLAGS) \
 @ENABLE_LIBDRUNTIME_ONLY_FALSE@	std/experimental/typecons.d std/file.d std/format/internal/floats.d \
 @ENABLE_LIBDRUNTIME_ONLY_FALSE@	std/format/internal/read.d std/format/internal/write.d \
 @ENABLE_LIBDRUNTIME_ONLY_FALSE@	std/format/package.d std/format/read.d std/format/spec.d \
-@ENABLE_LIBDRUNTIME_ONLY_FALSE@	std/format/write.d std/functional.d std/getopt.d \
+@ENABLE_LIBDRUNTIME_ONLY_FALSE@	std/format/write.d std/functional.d std/getopt.d std/int128.d \
 @ENABLE_LIBDRUNTIME_ONLY_FALSE@	std/internal/attributes.d std/internal/cstring.d \
 @ENABLE_LIBDRUNTIME_ONLY_FALSE@	std/internal/math/biguintcore.d std/internal/math/biguintnoasm.d \
 @ENABLE_LIBDRUNTIME_ONLY_FALSE@	std/internal/math/errorfunction.d std/internal/math/gammafunction.d \
@@ -846,6 +847,7 @@ std/format/spec.lo: std/format/$(am__dirstamp)
 std/format/write.lo: std/format/$(am__dirstamp)
 std/functional.lo: std/$(am__dirstamp)
 std/getopt.lo: std/$(am__dirstamp)
+std/int128.lo: std/$(am__dirstamp)
 std/internal/$(am__dirstamp):
 	@$(MKDIR_P) std/internal
 	@: > std/internal/$(am__dirstamp)
diff --git a/libphobos/src/std/base64.d b/libphobos/src/std/base64.d
index 866f7005060..d971dba1c71 100644
--- a/libphobos/src/std/base64.d
+++ b/libphobos/src/std/base64.d
@@ -63,7 +63,7 @@ import std.range.primitives : empty, front, isInputRange, isOutputRange,
 import std.traits : isArray;
 
 // Make sure module header code examples work correctly.
-@safe unittest
+pure @safe unittest
 {
     ubyte[] data = [0x14, 0xfb, 0x9c, 0x03, 0xd9, 0x7e];
 
@@ -82,7 +82,7 @@ import std.traits : isArray;
 alias Base64 = Base64Impl!('+', '/');
 
 ///
-@safe unittest
+pure @safe unittest
 {
     ubyte[] data = [0x83, 0xd7, 0x30, 0x7a, 0x01, 0x3f];
     assert(Base64.encode(data) == "g9cwegE/");
@@ -98,7 +98,7 @@ alias Base64 = Base64Impl!('+', '/');
 alias Base64URL = Base64Impl!('-', '_');
 
 ///
-@safe unittest
+pure @safe unittest
 {
     ubyte[] data = [0x83, 0xd7, 0x30, 0x7a, 0x01, 0x3f];
     assert(Base64URL.encode(data) == "g9cwegE_");
@@ -114,7 +114,7 @@ alias Base64URL = Base64Impl!('-', '_');
 alias Base64URLNoPadding = Base64Impl!('-', '_', Base64.NoPadding);
 
 ///
-@safe unittest
+pure @safe unittest
 {
     ubyte[] data = [0x83, 0xd7, 0x30, 0x7b, 0xef];
     assert(Base64URLNoPadding.encode(data) == "g9cwe-8");
@@ -180,7 +180,7 @@ template Base64Impl(char Map62th, char Map63th, char Padding = '=')
      * Returns:
      *  The length of a Base64 encoding of an array of the given length.
      */
-    @safe
+    @safe @nogc
     pure nothrow size_t encodeLength(in size_t sourceLength)
     {
         static if (Padding == NoPadding)
@@ -218,8 +218,8 @@ template Base64Impl(char Map62th, char Map63th, char Padding = '=')
      *  The slice of $(D_PARAM buffer) that contains the encoded string.
      */
     @trusted
-    pure char[] encode(R1, R2)(in R1 source, return scope R2 buffer) if (isArray!R1 && is(ElementType!R1 : ubyte) &&
-                                                            is(R2 == char[]))
+    pure char[] encode(R1, R2)(const scope R1 source, return scope R2 buffer)
+    if (isArray!R1 && is(ElementType!R1 : ubyte) && is(R2 == char[]))
     in
     {
         assert(buffer.length >= encodeLength(source.length), "Insufficient buffer for encoding");
@@ -277,9 +277,9 @@ template Base64Impl(char Map62th, char Map63th, char Padding = '=')
     }
 
     ///
-    @safe unittest
+    @nogc nothrow @safe unittest
     {
-        ubyte[] data = [0x83, 0xd7, 0x30, 0x7a, 0x01, 0x3f];
+        ubyte[6] data = [0x83, 0xd7, 0x30, 0x7a, 0x01, 0x3f];
         char[32] buffer;    // much bigger than necessary
 
         // Just to be sure...
@@ -287,7 +287,7 @@ template Base64Impl(char Map62th, char Map63th, char Padding = '=')
         assert(buffer.length >= encodedLength);
 
         // encode() returns a slice to the provided buffer.
-        auto encoded = Base64.encode(data, buffer[]);
+        auto encoded = Base64.encode(data[], buffer[]);
         assert(encoded is buffer[0 .. encodedLength]);
         assert(encoded == "g9cwegE/");
     }
diff --git a/libphobos/src/std/int128.d b/libphobos/src/std/int128.d
new file mode 100644
index 00000000000..fc992f82422
--- /dev/null
+++ b/libphobos/src/std/int128.d
@@ -0,0 +1,374 @@
+// Written in the D programming language
+/**
+ * Implements a signed 128 bit integer type.
+ *
+    Author:     Walter Bright
+    Copyright:  Copyright (c) 2022, D Language Foundation
+    License:    $(HTTP boost.org/LICENSE_1_0.txt, Boost License 1.0)
+    Source:     $(PHOBOSSRC std/int128.d)
+ */
+module std.int128;
+
+private import core.int128;
+
+
+/***********************************
+ * 128 bit signed integer type.
+ */
+
+public struct Int128
+{
+  @safe pure nothrow @nogc:
+
+    Cent data;          /// core.int128.Cent
+
+    /****************
+     * Construct an `Int128` from a `long` value.
+     * The upper 64 bits are formed by sign extension.
+     * Params:
+     *  lo = signed lower 64 bits
+     */
+    this(long lo)
+    {
+        data.lo = lo;
+        data.hi = lo < 0 ? ~0L : 0;
+    }
+
+    /****************
+     * Construct an `Int128` from a `ulong` value.
+     * The upper 64 bits are set to zero.
+     * Params:
+     *  lo = unsigned lower 64 bits
+     */
+    this(ulong lo)
+    {
+        data.lo = lo;
+        data.hi = 0;
+    }
+
+    /****************
+     * Construct an `Int128` from a `long` value.
+     * Params:
+     *  hi = upper 64 bits
+     *  lo = lower 64 bits
+     */
+    this(long hi, long lo)
+    {
+        data.hi = hi;
+        data.lo = lo;
+    }
+
+    /********************
+     * Construct an `Int128` from a `Cent`.
+     * Params:
+     *  data = Cent data
+     */
+    this(Cent data)
+    {
+        this.data = data;
+    }
+
+    /********************
+     * Returns: hash value for Int128
+     */
+    size_t toHash() const
+    {
+        return cast(size_t)((data.lo & 0xFFFF_FFFF) + (data.hi & 0xFFFF_FFFF) + (data.lo >> 32) + (data.hi >> 32));
+    }
+
+    /************************
+     * Compare for equality
+     * Params: lo = signed value to compare with
+     * Returns: true if Int128 equals value
+     */
+    bool opEquals(long lo) const
+    {
+        return data.lo == lo && data.hi == (lo >> 63);
+    }
+
+    /************************
+     * Compare for equality
+     * Params: lo = unsigned value to compare with
+     * Returns: true if Int128 equals value
+     */
+    bool opEquals(ulong lo) const
+    {
+        return data.hi == 0 && data.lo == lo;
+    }
+
+    /************************
+     * Compare for equality
+     * Params: op2 = value to compare with
+     * Returns: true if Int128 equals value
+     */
+    bool opEquals(Int128 op2) const
+    {
+        return data.hi == op2.data.hi && data.lo == op2.data.lo;
+    }
+
+    /** Support unary arithmentic operator +
+     * Params: op = "+"
+     * Returns: lvalue of result
+     */
+    Int128 opUnary(string op)() const
+        if (op == "+")
+    {
+        return this;
+    }
+
+    /** Support unary arithmentic operator - ~
+     * Params: op = "-", "~"
+     * Returns: lvalue of result
+     */
+    Int128 opUnary(string op)() const
+        if (op == "-" || op == "~")
+    {
+        static if (op == "-")
+            return Int128(neg(this.data));
+        else static if (op == "~")
+            return Int128(com(this.data));
+    }
+
+    /** Support unary arithmentic operator ++ --
+     * Params: op = "++", "--"
+     * Returns: lvalue of result
+     */
+    Int128 opUnary(string op)()
+        if (op == "++" || op == "--")
+    {
+        static if (op == "++")
+            this.data = inc(this.data);
+        else static if (op == "--")
+            this.data = dec(this.data);
+        else
+            static assert(0, op);
+        return this;
+    }
+
+    /** Support casting to a bool
+     * Params: T = bool
+     * Returns: boolean result
+     */
+    bool opCast(T : bool)() const
+    {
+        return tst(this.data);
+    }
+
+    /** Support binary arithmetic operators + - * / % & | ^ << >> >>>
+     * Params:
+     *   op = one of the arithmetic binary operators
+     *   op2 = second operand
+     * Returns: value after the operation is applied
+     */
+    Int128 opBinary(string op)(Int128 op2) const
+        if (op == "+" || op == "-" ||
+            op == "*" || op == "/" || op == "%" ||
+            op == "&" || op == "|" || op == "^")
+    {
+        static if (op == "+")
+            return Int128(add(this.data, op2.data));
+        else static if (op == "-")
+            return Int128(sub(this.data, op2.data));
+        else static if (op == "*")
+            return Int128(mul(this.data, op2.data));
+        else static if (op == "/")
+            return Int128(div(this.data, op2.data));
+        else static if (op == "%")
+        {
+            Cent modulus;
+            divmod(this.data, op2.data, modulus);
+            return Int128(modulus);
+        }
+        else static if (op == "&")
+            return Int128(and(this.data, op2.data));
+        else static if (op == "|")
+            return Int128(or(this.data, op2.data));
+        else static if (op == "^")
+            return Int128(xor(this.data, op2.data));
+        else
+            static assert(0, "wrong op value");
+    }
+
+    /// ditto
+    Int128 opBinary(string op)(long op2) const
+        if (op == "+" || op == "-" ||
+            op == "*" || op == "/" || op == "%" ||
+            op == "&" || op == "|" || op == "^")
+    {
+        return mixin("this " ~ op ~ " Int128(0, op2)");
+    }
+
+    /// ditto
+    Int128 opBinaryRight(string op)(long op2) const
+        if (op == "+" || op == "-" ||
+            op == "*" || op == "/" || op == "%" ||
+            op == "&" || op == "|" || op == "^")
+    {
+        mixin("return Int128(0, op2) " ~ op ~ " this;");
+    }
+
+    /// ditto
+    Int128 opBinary(string op)(long op2) const
+        if (op == "<<")
+    {
+        return Int128(shl(this.data, cast(uint) op2));
+    }
+
+    /// ditto
+    Int128 opBinary(string op)(long op2) const
+        if (op == ">>")
+    {
+        return Int128(sar(this.data, cast(uint) op2));
+    }
+
+    /// ditto
+    Int128 opBinary(string op)(long op2) const
+        if (op == ">>>")
+    {
+        return Int128(shr(this.data, cast(uint) op2));
+    }
+
+    /** arithmetic assignment operators += -= *= /= %= &= |= ^= <<= >>= >>>=
+     * Params: op = one of +, -, etc.
+     *   op2 = second operand
+     * Returns: lvalue of updated left operand
+     */
+    ref Int128 opOpAssign(string op)(Int128 op2)
+        if (op == "+" || op == "-" ||
+            op == "*" || op == "/" || op == "%" ||
+            op == "&" || op == "|" || op == "^" ||
+            op == "<<" || op == ">>" || op == ">>>")
+    {
+        mixin("this = this " ~ op ~ " op2;");
+        return this;
+    }
+
+    /// ditto
+    ref Int128 opOpAssign(string op)(long op2)
+        if (op == "+" || op == "-" ||
+            op == "*" || op == "/" || op == "%" ||
+            op == "&" || op == "|" || op == "^" ||
+            op == "<<" || op == ">>" || op == ">>>")
+    {
+        mixin("this = this " ~ op ~ " op2;");
+        return this;
+    }
+
+    /** support signed arithmentic comparison operators < <= > >=
+     * Params: op2 = right hand operand
+     * Returns: -1 for less than, 0 for equals, 1 for greater than
+     */
+    int opCmp(Int128 op2) const
+    {
+        return this == op2 ? 0 : gt(this.data, op2.data) * 2 - 1;
+    }
+
+    /** support signed arithmentic comparison operators < <= > >=
+     * Params: op2 = right hand operand
+     * Returns: -1 for less than, 0 for equals, 1 for greater than
+     */
+    int opCmp(long op2) const
+    {
+        return opCmp(Int128(0, op2));
+    }
+
+    enum min = Int128(long.min, 0);             /// minimum value
+    enum max = Int128(long.max, ulong.max);     /// maximum value
+}
+
+/********************************************* Tests ************************************/
+
+version (unittest)
+{
+import core.stdc.stdio;
+
+@trusted void print(Int128 c)
+{
+    printf("%lld, %lld\n", c.data.hi, c.data.lo);
+}
+
+@trusted void printx(Int128 c)
+{
+    printf("%llx, %llx\n", c.data.hi, c.data.lo);
+}
+}
+
+/// Int128 tests
+@safe pure nothrow @nogc
+unittest
+{
+    Int128 c = Int128(5, 6);
+    assert(c == c);
+    assert(c == +c);
+    assert(c == - -c);
+    assert(~c == Int128(~5, ~6));
+    ++c;
+    assert(c == Int128(5, 7));
+    assert(--c == Int128(5, 6));
+    assert(!!c);
+    assert(!Int128());
+
+    assert(c + Int128(10, 20) == Int128(15, 26));
+    assert(c - Int128(1, 2)   == Int128(4, 4));
+    assert(c * Int128(100, 2) == Int128(610, 12));
+    assert(c / Int128(3, 2)   == Int128(0, 1));
+    assert(c % Int128(3, 2)   == Int128(2, 4));
+    assert((c & Int128(3, 2)) == Int128(1, 2));
+    assert((c | Int128(3, 2)) == Int128(7, 6));
+    assert((c ^ Int128(3, 2)) == Int128(6, 4));
+
+    assert(c + 15   == Int128(5, 21));
+    assert(c - 15   == Int128(4, -9));
+    assert(c * 15   == Int128(75, 90));
+    assert(c / 15   == Int128(0, 6148914691236517205));
+    assert(c % 15   == Int128(0, 11));
+    assert((c & 15) == Int128(0, 6));
+    assert((c | 15) == Int128(5, 15));
+    assert((c ^ 15) == Int128(5, 9));
+
+    assert(15 + c   == Int128(5, 21));
+    assert(15 - c   == Int128(-5, 9));
+    assert(15 * c   == Int128(75, 90));
+    assert(15 / c   == Int128(0, 0));
+    assert(15 % c   == Int128(0, 15));
+    assert((15 & c) == Int128(0, 6));
+    assert((15 | c) == Int128(5, 15));
+    assert((15 ^ c) == Int128(5, 9));
+
+    assert(c << 1 == Int128(10, 12));
+    assert(-c >> 1 == Int128(-3, 9223372036854775805));
+    assert(-c >>> 1 == Int128(9223372036854775805, 9223372036854775805));
+
+    assert((c += 1) == Int128(5, 7));
+    assert((c -= 1) == Int128(5, 6));
+    assert((c += Int128(0, 1)) == Int128(5, 7));
+    assert((c -= Int128(0, 1)) == Int128(5, 6));
+    assert((c *= 2) == Int128(10, 12));
+    assert((c /= 2) == Int128(5, 6));
+    assert((c %= 2) == Int128());
+    c += Int128(5, 6);
+    assert((c *= Int128(10, 20)) == Int128(160, 120));
+    assert((c /= Int128(10, 20)) == Int128(0, 15));
+    c += Int128(72, 0);
+    assert((c %= Int128(10, 20)) == Int128(1, -125));
+    assert((c &= Int128(3, 20)) == Int128(1, 0));
+    assert((c |= Int128(8, 2)) == Int128(9, 2));
+    assert((c ^= Int128(8, 2)) == Int128(1, 0));
+    c |= Int128(10, 5);
+    assert((c <<= 1) == Int128(11 * 2, 5 * 2));
+    assert((c >>>= 1) == Int128(11, 5));
+    c = Int128(long.min, long.min);
+    assert((c >>= 1) == Int128(long.min >> 1, cast(ulong) long.min >> 1));
+
+    assert(-Int128.min == Int128.min);
+    assert(Int128.max + 1 == Int128.min);
+
+    c = Int128(5, 6);
+    assert(c < Int128(6, 5));
+    assert(c > 10);
+
+    c = Int128(-1UL);
+    assert(c == -1UL);
+    c = Int128(-1L);
+    assert(c == -1L);
+}
diff --git a/libphobos/src/std/path.d b/libphobos/src/std/path.d
index 20518b86333..de180fcc548 100644
--- a/libphobos/src/std/path.d
+++ b/libphobos/src/std/path.d
@@ -1519,7 +1519,7 @@ if (isSomeChar!C)
     import std.range;
     // ir() wraps an array in a plain (i.e. non-forward) input range, so that
     // we can test both code paths
-    InputRange!(C[]) ir(C)(C[][] p...) { return inputRangeObject(p); }
+    InputRange!(C[]) ir(C)(C[][] p...) { return inputRangeObject(p.dup); }
     version (Posix)
     {
         assert(buildPath("foo") == "foo");
diff --git a/libphobos/src/std/traits.d b/libphobos/src/std/traits.d
index 9ca676d312a..18400e3e859 100644
--- a/libphobos/src/std/traits.d
+++ b/libphobos/src/std/traits.d
@@ -1422,6 +1422,11 @@ if (isCallable!func)
             enum val = "val" ~ (name == "val" ? "_" : "");
             enum ptr = "ptr" ~ (name == "ptr" ? "_" : "");
             mixin("
+                enum hasDefaultArg = (PT[i .. i+1] " ~ args ~ ") { return true; };
+            ");
+            static if (is(typeof(hasDefaultArg())))
+            {
+                mixin("
                 // workaround scope escape check, see
                 // https://issues.dlang.org/show_bug.cgi?id=16582
                 // should use return scope once available
@@ -1432,10 +1437,9 @@ if (isCallable!func)
                     auto " ~ val ~ " = " ~ args ~ "[0];
                     auto " ~ ptr ~ " = &" ~ val ~ ";
                     return *" ~ ptr ~ ";
-                };
-            ");
-            static if (is(typeof(get())))
+                };");
                 enum Get = get();
+            }
             else
                 alias Get = void;
                 // If default arg doesn't exist, returns void instead.
@@ -1483,6 +1487,17 @@ if (isCallable!func)
     static foreach (V; Voids) static assert(is(V == void));
 }
 
+// https://issues.dlang.org/show_bug.cgi?id=20182
+@safe pure nothrow @nogc unittest
+{
+    struct S
+    {
+        this(ref S) {}
+    }
+
+    static assert(__traits(compiles, ParameterDefaults!(S.__ctor)));
+}
+
 /**
  * Alternate name for $(LREF ParameterDefaults), kept for legacy compatibility.
  */