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

@@ -29,15 +29,20 @@
 /*      Copyright (c) 1988 AT&T */
 /*        All Rights Reserved   */
 
 /* Copyright (c) 2013, OmniTI Computer Consulting, Inc. All rights reserved. */
 
+/*
+ * Copyright 2014 PALO, Richard.
+ */
+
 #ifndef _UNISTD_H
 #define _UNISTD_H
 
 #include <sys/feature_tests.h>
 
+#include <sys/null.h>
 #include <sys/types.h>
 #include <sys/unistd.h>
 
 #ifdef  __cplusplus
 extern "C" {

@@ -176,18 +181,10 @@
 
 #ifndef _POSIX_VDISABLE
 #define _POSIX_VDISABLE         0
 #endif
 
-#ifndef NULL
-#if defined(_LP64)
-#define NULL    0L
-#else
-#define NULL    0
-#endif
-#endif
-
 #define STDIN_FILENO    0
 #define STDOUT_FILENO   1
 #define STDERR_FILENO   2
 
 /*