Rebase fixup

Zend/zend_inheritance.c

@@ -643,7 +643,7 @@ static inheritance_status zend_perform_covariant_type_check(
  * subtype of a parent single/intersection type, either it is an INvalid subtype
  * when the parent is a union or it is unresolved, we check which case this is */
 if (ZEND_TYPE_IS_UNION(proto_type) && !parent_union_has_unresolved) {
-return tentative ? INHERITANCE_WARNING : INHERITANCE_ERROR;
+return INHERITANCE_ERROR;
 }
 } else {
 /* First try to check whether we can succeed without resolving anything */