* c-opts.c (c_common_post_options):  Don't call cpp_find_main_file yet.
	(c_common_parse_file):  No longer need to call cpp_read_main_file
	when file_index > 0 (as in multi-file or server compiation).
	(finish_options):  Change to <built-in> is an LC_ENTER, not LC_RENAME
	as this now happens before cpp_push_main_file.
	(push_command_line_include):  When done with options, pass LC_LEAVE
	instead of LC_RENAME to cpp_change_file and finally cpp_push_main_file.
	(fe_file_change):  Handle NULL new_map, and simplify.

From-SVN: r72015