https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84676
--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Untested fix:
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -5591,6 +5591,10 @@ build_new_op_1 (location_t loc, enum tree_code code, int
flags, tree arg1,
|| error_operand_p (arg3))
return error_mark_node;
+ if (TREE_TYPE (arg1) == NULL_TREE
+ || TREE_TYPE (arg2) == NULL_TREE)
+ return error_mark_node;
+
bool ismodop = code == MODIFY_EXPR;
if (ismodop)
{
