objc-act.c (generate_method_descriptors): Register objc_method_prototype_template...

objc-act.c (generate_method_descriptors): Register objc_method_prototype_template as a GC root.

	* objc/objc-act.c (generate_method_descriptors): Register
	objc_method_prototype_template as a GC root.
	(comp_method_with_proto): Register function_type as a GC root.
	(comp_proto_with_proto): Replace function_type1 and
	function_type2 with a two-element array; register it as a GC root.

	(generate_protocols, build_protocol_initializer,
	generate_protocol_list, build_category_initializer,
	build_shared_structure_initializer): Do not cache cast_type
	and/or cast_type2.

From-SVN: r34405