stddef.h: Simplify conditions around avoiding re-definition of __size_t.

	* ginclude/stddef.h: Simplify conditions around avoiding
	re-definition of __size_t.

From-SVN: r261998

gcc/ChangeLog

+2018-06-24  Maya Rashish  <coypu@sdf.org>
+
+	* ginclude/stddef.h: Simplify conditions around avoiding
+	re-definition of __size_t.
+
 2018-06-22  Jan Hubicka  <hubicka@ucw.cz>
 
 	* lto-streamer-out.c (tree_is_indexable): Make LABEL_DECL nonindexable

gcc/ginclude/stddef.h

@@ -196,10 +196,9 @@ typedef __PTRDIFF_TYPE__ ptrdiff_t;
 #define _SIZET_
 #if (defined (__FreeBSD__) && (__FreeBSD__ >= 5)) \
   || defined(__DragonFly__) \
-  || defined(__FreeBSD_kernel__)
-/* __size_t is a typedef on FreeBSD 5, must not trash it. */
-#elif defined (__VMS__)
-/* __size_t is also a typedef on VMS.  */
+  || defined(__FreeBSD_kernel__) \
+  || defined(__VMS__)
+/* __size_t is a typedef, must not trash it.  */
 #else
 #define __size_t
 #endif