LibC: Move size_t, ptrdiff_t and NULL to stddef.h. #POSIX

LibC/stddef.h

@@ -2,3 +2,12 @@
 
 #include <sys/cdefs.h>
 #include <sys/types.h>
+
+#ifdef __cplusplus
+#define NULL nullptr
+#else
+#define NULL ((void*)0)
+#endif
+
+typedef __PTRDIFF_TYPE__ ptrdiff_t;
+typedef __SIZE_TYPE__ size_t;

LibC/sys/types.h

@@ -1,7 +1,8 @@
 #pragma once
 
-#include <sys/cdefs.h>
+#include <stddef.h>
 #include <stdint.h>
+#include <sys/cdefs.h>
 
 __BEGIN_DECLS
 
@@ -14,7 +15,6 @@ typedef uint32_t gid_t;
 typedef int __pid_t;
 #define pid_t __pid_t
 
-typedef __SIZE_TYPE__ size_t;
 typedef int __ssize_t;
 #define ssize_t __ssize_t
 
@@ -58,11 +58,5 @@ struct utimbuf {
     time_t modtime;
 };
 
-#ifdef __cplusplus
-#define NULL nullptr
-#else
-#define NULL 0
-#endif
-
 __END_DECLS