Fix more variadic capture issues.

Fix more variadic capture issues.

	* pt.c (find_parameter_packs_r): Also look at explicit captures.
	(check_for_bare_parameter_packs): Check current_class_type for
	lambda context.
	(extract_locals_r): Handle seeing a full instantiation of a pack.
	(tsubst_pack_expansion): Likewise.  Force lambda capture.
	* parser.c (cp_parser_lambda_introducer): Don't
	check_for_bare_parameter_packs.

From-SVN: r257627