[promises] cleanup default promise handlers

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index 142ff8eb1e08dbe253326c7276ccc0df1c394346..e01456719d810a47815cde2fd2e4ec35f2c47b61 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -1878,6 +1878,11 @@ bool InternalPromiseHasUserDefinedRejectHandler(Isolate* isolate,
                                Handle<JSReceiver>::cast(deferred_promise));
   }
 
+  if (queue->IsSymbol()) {
+    return InternalPromiseHasUserDefinedRejectHandler(
+        isolate, Handle<JSPromise>::cast(deferred_promise));
+  }
+
   Handle<FixedArray> queue_arr = Handle<FixedArray>::cast(queue);
   Handle<FixedArray> deferred_promise_arr =
       Handle<FixedArray>::cast(deferred_promise);