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

sdk/lib/_internal/pub_generated/test/get/git/require_pubspec_test.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS 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';
 
 main() {
   initConfig();
   integration('requires the dependency to have a pubspec', () {
     ensureGit();
 
-    d.git('foo.git', [
-      d.libDir('foo')
-    ]).create();
+    d.git('foo.git', [d.libDir('foo')]).create();
 
-    d.appDir({"foo": {"git": "../foo.git"}}).create();
+    d.appDir({
+      "foo": {
+        "git": "../foo.git"
+      }
+    }).create();
 
-    pubGet(error: new RegExp(r'Could not find a file named "pubspec\.yaml" '
-        r'in "[^\n]*"\.'));
+    pubGet(
+        error: new RegExp(
+            r'Could not find a file named "pubspec\.yaml" ' r'in "[^\n]*"\.'));
   });
 }