gcc.c: Include <strings.h>/<string.h>, <stdlib.h>, <unistd.h>, <fcntl.h>.

        * gcc.c: Include <strings.h>/<string.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>

From-SVN: r17768