Revert "Use native async/await support in pub."

sdk/lib/_internal/pub_generated/test/transformer/fails_to_load_a_non_existent_transform_test.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS d.file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library pub_tests;
 
 import '../descriptor.dart' as d;
 import '../test_pub.dart';
 import '../serve/utils.dart';
 
 main() {
   initConfig();
   withBarbackVersions("any", () {
     integration("fails to load a non-existent transform", () {
-      d.dir(appPath, [
-        d.pubspec({
+      d.dir(appPath, [d.pubspec({
           "name": "myapp",
           "transformers": ["myapp/transform"]
-        })
-      ]).create();
+        })]).create();
 
       var pub = startPubServe();
       pub.stderr.expect(
           'Transformer library "package:myapp/transform.dart" not found.');
       pub.shouldExit(1);
     });
   });
 }