* hashtab.c, partition.c, xmemdup.c: Include string.h

if HAVE_STRING_H.
	* pexecute.c, xexit.c: Include stdlib.h if HAVE_STDLIB_H.
	* objalloc.c: Include config.h.  Include stdlib.h and don't
	declare malloc or free if HAVE_STDLIB_H.
	* strerror.c, strsignal.c: Include stdlib.h if HAVE_STDLIB_H,
	else declare malloc without prototype.  Include string.h if
	HAVE_STRING_H, else declare memset without prototype.  Don't
	include stddef.h.

	* sort.c: Bring over from GCC.

libiberty/xexit.c

@@ -21,6 +21,9 @@ Boston, MA 02111-1307, USA.  */
 #include "libiberty.h"
 
 #include <stdio.h>
+#ifdef HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
 
 /* This variable is set by xatexit if it is called.  This way, xmalloc
    doesn't drag xatexit into the link.  */