Remove now-obsolete __STDC__ ifdefs, remove redundant NULL definition and

include stdlib.h for NULL.

bin/sh/mkbuiltins

@@ -54,6 +54,7 @@ cat <<\!
  * This file was generated by the mkbuiltins program.
  */
 
+#include <stdlib.h>
 #include "shell.h"
 #include "builtins.h"
 

bin/sh/output.h

@@ -39,11 +39,7 @@
 
 #ifndef OUTPUT_INCL
 
-#ifdef __STDC__
 #include <stdarg.h>
-#else
-#include <varargs.h>
-#endif
 
 struct output {
 	char *nextc;

bin/sh/shell.h

@@ -57,17 +57,7 @@
 #endif
 /* #define DEBUG 1 */
 
-#ifdef __STDC__
 typedef void *pointer;
-#ifndef NULL
-#define NULL (void *)0
-#endif
-#else /* not __STDC__ */
-typedef char *pointer;
-#ifndef NULL
-#define NULL 0
-#endif
-#endif /*  not __STDC__ */
 #define STATIC  static
 #define MKINIT	/* empty */