Use the alternate form of the gcc extension that works even with

-ansi -pedantic without issuing a warning, and which is recommended
by gcc manual.

MFC after:	1 week

sys/sys/param.h

@@ -324,6 +324,6 @@ __END_DECLS
  * Access a variable length array that has been declared as a fixed
  * length array.
  */
-#define __PAST_END(array, offset) (((typeof(*(array)) *)(array))[offset])
+#define __PAST_END(array, offset) (((__typeof__(*(array)) *)(array))[offset])
 
 #endif	/* _SYS_PARAM_H_ */