DR 1207
	PR c++/49003
	* cp-tree.h (struct saved_scope): Add x_current_class_ptr,
	x_current_class_ref.
	(current_class_ptr, current_class_ref): Use them.
	* decl.c (build_this_parm): Handle getting the class type.
	* parser.c (cp_parser_late_return_type_opt): Set up 'this'
	for use within the trailing return type.

From-SVN: r175671