re PR c++/63885 (ICE in static assert of constexpr forwarding xvalue container member rvalue reference)

	PR c++/63885
	* constexpr.c (cxx_eval_constant_expression) [PARM_DECL]: Don't
	complain yet about a reference.
	[TARGET_EXPR]: Handle TARGET_EXPR with addr == true.
	[ADDR_EXPR]: Make sure we don't take the address of a CONSTRUCTOR.
	(cxx_bind_parameters_in_call): In the new scheme addr is always false.
	* typeck.c (build_address): Don't take the address of a CONSTRUCTOR.

From-SVN: r217815