* langhooks.c (lang_hook_default_clear_binding_stack): New.
	(lang_hook_default_get_alias_set): Move next to other alias
	hooks.
	* langhooks.h: Prototype lang_hook_default_clear_binding_stack.
	(LANG_HOOKS_CLEAR_BINDING_STACK): New macro.
	(LANG_HOOKS_INITIALIZER): Add it.
	* toplev.h (struct lang_hooks): Add clear_binding_stack.
	* toplev.c (compile_file):  Call lang_hooks.clear_binding_stack
	instead of a loop calling poplevel.
cp:
	* cp-lang.c: Redefine LANG_HOOKS_CLEAR_BINDING_STACK to
	pop_everything.

From-SVN: r46492