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

*** 244,254 ****
          get_token(line, &pos, line_len, uid, MISC_SIZE);
          get_token(line, &pos, line_len, gid, MISC_SIZE);
  
          /* Reset these fields... */
  
!         *contents = NULL;
          *devnode = '\0';
          *dest = '\0';
  
          /* Handle filetypes which have a last field..... */
          if (type[0] == 'F')
--- 244,254 ----
          get_token(line, &pos, line_len, uid, MISC_SIZE);
          get_token(line, &pos, line_len, gid, MISC_SIZE);
  
          /* Reset these fields... */
  
!         *contents = '\0';
          *devnode = '\0';
          *dest = '\0';
  
          /* Handle filetypes which have a last field..... */
          if (type[0] == 'F')