Core 975
	* decl.c (cxx_init_decl_processing): Initialize
	dependent_lambda_return_type_node.
	* cp-tree.h (cp_tree_index): Add CPTI_DEPENDENT_LAMBDA_RETURN_TYPE.
	(dependent_lambda_return_type_node): Define.
	(DECLTYPE_FOR_LAMBDA_RETURN): Remove.
	* semantics.c (lambda_return_type): Handle overloaded function.
	Use dependent_lambda_return_type_node instead of
	DECLTYPE_FOR_LAMBDA_RETURN.
	(apply_lambda_return_type): Don't check dependent_type_p.
	* pt.c (tsubst_copy_and_build): Handle lambda return type deduction.
	(instantiate_class_template_1): Likewise.
	(tsubst): Don't use DECLTYPE_FOR_LAMBDA_RETURN.
	* mangle.c (write_type): Likewise.
	* typeck.c (structural_comptypes): Likewise.
	(check_return_expr): Handle dependent_lambda_return_type_node.

From-SVN: r177995