https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64603
--- Comment #4 from janus at gcc dot gnu.org ---
(In reply to Jakub Jelinek from comment #3)
> Started with r217664.
Confirmed. Reverting that guy fixes the problem:
Index: gcc/cp/constexpr.c
===================================================================
--- gcc/cp/constexpr.c (Revision 219840)
+++ gcc/cp/constexpr.c (Arbeitskopie)
@@ -1049,7 +1049,7 @@ adjust_temp_type (tree type, tree temp)
/* True if we want to use the new handling of constexpr calls based on
DECL_SAVED_TREE. */
-#define use_new_call true
+#define use_new_call (cxx_dialect >= cxx14)
/* Subroutine of cxx_eval_call_expression.
We are processing a call expression (either CALL_EXPR or
