define some _POSIX_* macros that were omitted; required for XSI conformance

include/unistd.h

@@ -211,6 +211,7 @@ void syncfs(int);
 #define _POSIX_MEMLOCK          _POSIX_VERSION
 #define _POSIX_MEMLOCK_RANGE    _POSIX_VERSION
 #define _POSIX_MEMORY_PROTECTION _POSIX_VERSION
+#define _POSIX_FSYNC            _POSIX_VERSION
 #define _POSIX_NO_TRUNC         1
 #define _POSIX_RAW_SOCKETS      _POSIX_VERSION
 #define _POSIX_REALTIME_SIGNALS _POSIX_VERSION
@@ -222,6 +223,8 @@ void syncfs(int);
 #define _POSIX_THREADS          _POSIX_VERSION
 #define _POSIX_THREAD_PROCESS_SHARED _POSIX_VERSION
 #define _POSIX_THREAD_SAFE_FUNCTIONS _POSIX_VERSION
+#define _POSIX_THREAD_ATTR_STACKADDR _POSIX_VERSION
+#define _POSIX_THREAD_ATTR_STACKSIZE _POSIX_VERSION
 #define _POSIX_TIMERS           _POSIX_VERSION
 #define _POSIX_TIMEOUTS         _POSIX_VERSION
 #define _POSIX_MONOTONIC_CLOCK  _POSIX_VERSION