PR c++/84192
	* constexpr.c (cxx_eval_constant_expression) <case RETURN_EXPR>: Don't
	set *jump_target to anything if jump_target is NULL.

	* g++.dg/cpp1y/constexpr-84192.C: New test.

Co-Authored-By: Jakub Jelinek <jakub@redhat.com>

From-SVN: r257770