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

@@ -123,11 +123,11 @@
 }
 
 void
 sdbc_report_error(spcs_s_info_t *ustatus)
 {
-        if (*ustatus != NULL) {
+        if (*ustatus != (uintptr_t)NULL) {
                 spcs_s_report(*ustatus, stderr);
                 spcs_s_ufree(ustatus);
         } else
                 (void) fprintf(stderr, "%s\n", strerror(errno));
 }