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

sdk/lib/_internal/pub_generated/test/get/path/path_is_file_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 d.file.
 
 import 'package:path/path.dart' as path;
 
 import '../../descriptor.dart' as d;
 import '../../test_pub.dart';
 
 main() {
   initConfig();
   integration('path dependency when path is a file', () {
-    d.dir('foo', [
-      d.libDir('foo'),
-      d.libPubspec('foo', '0.0.1')
-    ]).create();
+    d.dir('foo', [d.libDir('foo'), d.libPubspec('foo', '0.0.1')]).create();
 
     d.file('dummy.txt', '').create();
     var dummyPath = path.join(sandboxDir, 'dummy.txt');
 
-    d.dir(appPath, [
-      d.appPubspec({
-        "foo": {"path": dummyPath}
-      })
-    ]).create();
+    d.dir(appPath, [d.appPubspec({
+        "foo": {
+          "path": dummyPath
+        }
+      })]).create();
 
-    pubGet(error: 'Path dependency for package foo must refer to a '
-                  'directory, not a file. Was "$dummyPath".');
+    pubGet(
+        error: 'Path dependency for package foo must refer to a '
+            'directory, not a file. Was "$dummyPath".');
   });
-}
+}