* toplev.c (parse_options_and_default_flags): Don't call
	post_options here.
	(general_init): Initialize GC, pools and tree hash here,
	instead of lang_independent_init.
	(lang_independent_init): Rename backend_init.
	(do_compile): Call post_options hook; exit early if there
	have been errors after switch processing.
	(toplev_main): Update.

From-SVN: r56274