PR c++/54341
	PR c++/54253
	* semantics.c (sort_constexpr_mem_initializers): New.
	(build_constexpr_constructor_member_initializers): Use it.
	(cx_check_missing_mem_inits): Skip artificial fields.
	* init.c (expand_aggr_init_1): Don't zero out a class
	with no data.

From-SVN: r191033