Update.

Update.

	* misc/sys/cdefs.h: Define __attribute_malloc__ according to
	available gcc version.
	* string/string.h: Mark strdup, __strdup, and strndup with
	__attribute_malloc__.
	* stdlib/stdlib.h: Make malloc, calloc, realloc, and valloc with
	__attribute_malloc__.
	* malloc/malloc.h: Make malloc, calloc, realloc, valloc, pvallc,
	__morecore, and __default_morecore with __attribute_malloc__.
	Provide default definition for __attribute_malloc__.
	* libio/stdio.h: Make tempnam with __attribute_malloc__.