re PR c++/92414 (internal compiler error: tree check: expected constructor, have error_mark in cxx_eval_store_expression, at cp/constexpr.c:4009)

	PR c++/92414
	* constexpr.c (cxx_eval_outermost_constant_expr): If DECL_INITIAL
	on object is erroneous, return t without trying to evaluate
	a constexpr dtor.

	* g++.dg/cpp2a/constexpr-dtor4.C: New test.

From-SVN: r278468