libstdc++: Move C++14 <chrono> components to new <bits/chrono.h> header

This moves the "classic" contents of <chrono> to a new header, so that
<future>, <thread> etc. can get use durations and clocks without
calendar types, time zones, and chrono I/O.

libstdc++-v3/ChangeLog:

	* include/Makefile.am: Add new header.
	* include/Makefile.in: Regenerate.
	* include/std/chrono (duration, time_point, system_clock)
	(steady_clock, high_resolution_clock, chrono_literals, sys_time)
	(file_clock, file_time): Move to ...
	* include/bits/chrono.h: New file.
	* include/bits/atomic_futex.h: Include new header instead of
	<chrono>.
	* include/bits/atomic_timed_wait.h: Likewise.
	* include/bits/fs_fwd.h: Likewise.
	* include/bits/semaphore_base.h: Likewise.
	* include/bits/this_thread_sleep.h: Likewise.
	* include/bits/unique_lock.h: Likewise.
	* include/experimental/bits/fs_fwd.h: Likewise.
	* include/experimental/chrono: Likewise.
	* include/experimental/io_context: Likewise.
	* include/experimental/netfwd: Likewise.
	* include/experimental/timer: Likewise.
	* include/std/condition_variable: Likewise.
	* include/std/mutex: Likewise.
	* include/std/shared_mutex: Likewise.

5 files changed, 5 insertions, 5 deletions

diff --git a/libstdc++-v3/include/experimental/bits/fs_fwd.h b/libstdc++-v3/include/experimental/bits/fs_fwd.h
index 8d63e095be5..243e571a52a 100644
--- a/libstdc++-v3/include/experimental/bits/fs_fwd.h
+++ b/libstdc++-v3/include/experimental/bits/fs_fwd.h
@@ -36,7 +36,7 @@
 
 #include <system_error>
 #include <cstdint>
-#include <chrono>
+#include <bits/chrono.h>
 
 namespace std _GLIBCXX_VISIBILITY(default)
 {
diff --git a/libstdc++-v3/include/experimental/chrono b/libstdc++-v3/include/experimental/chrono
index a38cb521678..8d66174bf6d 100644
--- a/libstdc++-v3/include/experimental/chrono
+++ b/libstdc++-v3/include/experimental/chrono
@@ -38,7 +38,7 @@
 
 #if __cplusplus >= 201402L
 
-#include <chrono>
+#include <bits/chrono.h> // Only the C++14 parts of <chrono>
 #include <experimental/bits/lfts_config.h>
 
 namespace std _GLIBCXX_VISIBILITY(default)
diff --git a/libstdc++-v3/include/experimental/io_context b/libstdc++-v3/include/experimental/io_context
index 63d7db5b2d0..f0e2e326885 100644
--- a/libstdc++-v3/include/experimental/io_context
+++ b/libstdc++-v3/include/experimental/io_context
@@ -35,7 +35,6 @@
 #if __cplusplus >= 201402L
 
 #include <atomic>
-#include <chrono>
 #include <forward_list>
 #include <functional>
 #include <system_error>
@@ -43,6 +42,7 @@
 #include <vector>
 #include <experimental/netfwd>
 #include <experimental/executor>
+#include <bits/chrono.h>
 #if _GLIBCXX_HAVE_UNISTD_H
 # include <unistd.h>
 #endif
diff --git a/libstdc++-v3/include/experimental/netfwd b/libstdc++-v3/include/experimental/netfwd
index b3315985067..31b938c2118 100644
--- a/libstdc++-v3/include/experimental/netfwd
+++ b/libstdc++-v3/include/experimental/netfwd
@@ -37,7 +37,7 @@
 // #define __cpp_lib_experimental_net 201803
 // #define __cpp_lib_experimental_net_extensible 201803
 
-#include <chrono>
+#include <bits/chrono.h>
 
 namespace std _GLIBCXX_VISIBILITY(default)
 {
diff --git a/libstdc++-v3/include/experimental/timer b/libstdc++-v3/include/experimental/timer
index e28efa3f3f3..d947a586a0a 100644
--- a/libstdc++-v3/include/experimental/timer
+++ b/libstdc++-v3/include/experimental/timer
@@ -34,7 +34,7 @@
 
 #if __cplusplus >= 201402L
 
-#include <chrono>
+#include <bits/chrono.h>
 #include <system_error>
 #include <thread>
 #include <experimental/netfwd>