Some new/fixed async tests

test/mjsunit/es6/debug-promises/async-task-event.js

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --expose-debug-as debug
+// Flags: --expose-debug-as debug --allow-natives-syntax
 
 Debug = debug.Debug;
 
 var base_id = -1;
 var exception = null;
 var expected = [
   "enqueue #1",
   "willHandle #1",
   "then #1",
   "enqueue #2",
   "didHandle #1",
   "willHandle #2",
   "then #2",
+  "didHandle #2",
   "enqueue #3",
-  "didHandle #2",
   "willHandle #3",
   "didHandle #3"
 ];
 
 function assertLog(msg) {
   print(msg);
   assertTrue(expected.length > 0);
   assertEquals(expected.shift(), msg);
   if (!expected.length) {
     Debug.setListener(null);
@@ skipping 20 matching lines @@
 var p = new Promise(function(resolve, reject) {
   resolver = resolve;
 });
 p.then(function() {
   assertLog("then #1");
 }).then(function() {
   assertLog("then #2");
 });
 resolver();
 
+%RunMicrotasks();
+
 assertNull(exception);