Description: add THROW for nanosleep

This fixes a build failure
 .
 glibc (2.31-2038.3) UNRELEASED; urgency=medium
 .
   [ Arnd Bergmann ]
   * Import https://github.com/lmajewski/y2038_glibc/commits/y2038_edge
   * Force-enable time64
   * rework a few more times
Author: Arnd Bergmann <arnd@arndb.de>

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Bug: <url in upstream bugtracker>
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Last-Update: 2020-03-05

--- glibc-2.31.orig/time/time.h
+++ glibc-2.31/time/time.h
@@ -311,7 +311,7 @@ extern int __REDIRECT_NTH (clock_settime
    __THROW.  */
 extern int clock_nanosleep (clockid_t __clock_id, int __flags,
 			    const struct timespec *__req,
-			    struct timespec *__rem);
+			    struct timespec *__rem) __THROW;
 
 #ifdef __USE_TIME_BITS64
 # if defined(__REDIRECT_NTH)