PR c++/65046
	Automatically propagate ABI tags to variables and functions
	from their (return) type.
	* class.c (check_tag): Handle variables and functions.
	(mark_or_check_attr_tags): Split out from find_abi_tags_r.
	(mark_or_check_tags): Likewise.
	(mark_abi_tags): Use it.  Rename from mark_type_abi_tags.
	(check_abi_tags): Add single argument overload for decls.
	Handle inheriting tags for decls.
	* mangle.c (write_mangled_name): Call it.
	(mangle_return_type_p): Split out from write_encoding.
	(unmangled_name_p): Split out from write_mangled_name.
	(write_mangled_name): Ignore abi_tag on namespace.
	* cp-tree.h (NAMESPACE_IS_INLINE): Replace NAMESPACE_ABI_TAG.
	* parser.c (cp_parser_namespace_definition): Set it.
	* name-lookup.c (handle_namespace_attrs): Use arguments. Warn
	about abi_tag attribute on non-inline namespace.
	* tree.c (check_abi_tag_args): Split out from handle_abi_tag_attribute.
	(handle_abi_tag_attribute): Allow tags on variables.

From-SVN: r221521