ZEND_ACC_NOT_SERIALIZABLE was introduced since PHP-8.1
This makes it easier for us to delete it later.
@@ -55,7 +55,7 @@ SWOW_API zend_class_entry *swow_register_internal_class(
parent_ce->ce_flags |= ZEND_ACC_FINAL;
}
if (!serializable) {
-#ifdef ZEND_ACC_NOT_SERIALIZABLE
+#ifdef ZEND_ACC_NOT_SERIALIZABLE /* PHP_VERSION_ID >= 80100 */
ce->ce_flags |= ZEND_ACC_NOT_SERIALIZABLE;
#else
ce->serialize = zend_class_serialize_deny;
