5218 posix definition of NULL
correct unistd.h and iso/stddef_iso.h
update gate source affected

@@ -27,10 +27,14 @@
  * Copyright 1999-2003 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
 /*
+ * Copyright 2014 PALO, Richard.
+ */
+
+/*
  * An application should not include this header directly.  Instead it
  * should be included only through the inclusion of other Sun headers.
  *
  * The contents of this header is limited to identifiers specified in the
  * C Standard.  Any new identifiers specified in future amendments to the

@@ -41,30 +45,21 @@
  */
 
 #ifndef _ISO_STDDEF_ISO_H
 #define _ISO_STDDEF_ISO_H
 
-#pragma ident   "%Z%%M% %I%     %E% SMI" /* SVr4.0 1.5 */
-
 #include <sys/isa_defs.h>
+#include <sys/null.h>
 
 #ifdef  __cplusplus
 extern "C" {
 #endif
 
 #if __cplusplus >= 199711L
 namespace std {
 #endif
 
-#ifndef NULL
-#if defined(_LP64)
-#define NULL    0L
-#else
-#define NULL    0
-#endif
-#endif
-
 #if !defined(_PTRDIFF_T) || __cplusplus >= 199711L
 #define _PTRDIFF_T
 #if defined(_LP64) || defined(_I32LPx)
 typedef long    ptrdiff_t;              /* pointer difference */
 #else