Remove --harmony-async-await runtime flag

test/debugger/debug/es8/async-function-debug-scopes.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
-
 var Debug = debug.Debug;
 var global_marker = 7;
 
 async function thrower() { throw 'Exception'; }
 
 async function test(name, func, args, handler, continuation) {
   var handler_called = false;
   var exception = null;
 
   function listener(event, exec_state, event_data, data) {
@@ skipping 524 matching lines @@
 
   if (scope_size < count) {
     print('Names found in scope:');
     var names = scope.scopeObject().propertyNames();
     for (var i = 0; i < names.length; i++) {
       print(names[i]);
     }
   }
   assertTrue(scope_size >= count);
 }