Revert of Fix async/await memory leak

test/mjsunit/harmony/debug-async-function-async-task-event.js

 // Copyright 2016 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: --harmony-async-await --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 #1",
+  "willHandle #1",
+  "then #1",
+  "enqueue #2",
+  "enqueue #3",
+  "didHandle #1",
+  "willHandle #2",
+  "then #2",
+  "didHandle #2",
+  "willHandle #3",
+  "enqueue #4",
+  "didHandle #3",
+  "willHandle #4",
+  "didHandle #4",
 ];
 
 function assertLog(msg) {
   print(msg);
   assertTrue(expected.length > 0);
   assertEquals(expected.shift(), msg);
   if (!expected.length) {
     Debug.setListener(null);
   }
 }
@@ skipping 25 matching lines @@
   assertLog("then #1");
   await undefined;
   assertLog("then #2");
 }
 main();
 resolver();
 
 %RunMicrotasks();
 
 assertNull(exception);