Define __USE_POSIX199309.
* posix/unistd.h: Declare fdatasync only if __USE_POSIX199309.
* time/time.c: Declare nanosleep only if __USE_POSIX199309.
- Patches by Rüdiger Helsch <rh@unifix.de>.
+ Patches by Rüdiger Helsch <rh@unifix.de>.
* locale/locale.h: Add declaration of newlocale and freelocale.