2007-08-31  Francois-Xavier Coudert  <fxcoudert@gcc.gnu.org>

	* gcc.c (xputenv): New function.
	(putenv_from_prefixes): Use xputenv instead of putenv.
	(process_command): Use xputenv instead of putenv.
	(set_collect_gcc_options): Use xputenv instead of putenv.
	(main): Use xputenv instead of putenv.