Use vector API for vbase list.

Use vector API for vbase list.

	* cp-tree.h: Include vec.h
	(DEF_VEC_P (tree)): New type.
	(struct lang_type_class): Change vbase's member type.
	(binfo_for_vbase): Declare.
	* class.c (determine_primary_base, base_derived_from,
	update_vtable_entry_for_fn, walk_subobject_offsets, end_of_class,
	warn_about_ambiguous_bases, dfs_accumulate_vtbl_inits,
	build_vtbl_initializer): Adjust.
	* decl.c (xref_basetypes): Adjust, accumulate upper bound of
	vbases.
	* init.c (sort_mem_initializers, expand_member_init,
	push_base_cleanups): Adjust.
	* method.c (do_build_copy_constructor): Adjust.
	* search.c (get_pure_virtuals, copied_binfo, original_binfo): Adjust.
	(binfo_for_vbase): New.
	* tree.c (copy_base_binfos): Adjust.

From-SVN: r83770