gcc.c warning cleanup

[Jeffrey A Law]

  In message < 19980206012704.07567@dgii.com >you write:
  > A few remain in this file, but I think that most of them are due to
  > the flow analysis thing (if/then/else) that somone (rth?) mentioned
  > recently.
  > 
  > 
  > Fri Feb  6 01:21:03 1998  Robert Lipe  <robertl@dgii.com>
  > 
  > 	* gcc.c Include <strings.h>, <stdlib.h>, <unistd.h>, <fcntl.h>.
  > 	(free_path_suffix): Remove unreferenced static function.
  > 	(process_command): Remove unused variable temp.
  > 	(default_arg): Remove unused variable i.
  > 	(do_spec_1):  Add parens for assignment used as truth value.
  > 	(main): Likewise.
  > 	(validate_all_switches): Likewise.
  > 	(main): Remove unused variables i, first_time>
I fixed up the strings/string issue and installed this patch.

jeff