Use native async/await support in pub.

sdk/lib/_internal/pub_generated/test/cache/repair/handles_orphaned_binstub_test.dart

-// Copyright (c) 2014, 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 'package:scheduled_test/scheduled_test.dart';
-
-import '../../descriptor.dart' as d;
-import '../../test_pub.dart';
-
-const _ORPHANED_BINSTUB = """
-#!/usr/bin/env sh
-# This file was created by pub v0.1.2-3.
-# Package: foo
-# Version: 1.0.0
-# Executable: foo-script
-# Script: script
-dart "/path/to/.pub-cache/global_packages/foo/bin/script.dart.snapshot" "\$@"
-""";
-
-main() {
-  initConfig();
-  integration('handles an orphaned binstub script', () {
-    d.dir(
-        cachePath,
-        [d.dir('bin', [d.file(binStubName('script'), _ORPHANED_BINSTUB)])]).create();
-
-    schedulePub(
-        args: ["cache", "repair"],
-        error: allOf(
-            [
-                contains('Binstubs exist for non-activated packages:'),
-                contains('From foo: foo-script')]));
-  });
-}