Use native async/await support in pub.

sdk/lib/_internal/pub_generated/test/get/hosted/get_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 '../../../lib/src/exit_codes.dart' as exit_codes;
-import '../../descriptor.dart' as d;
-import '../../test_pub.dart';
-
-main() {
-  initConfig();
-  integration('gets a package from a pub server', () {
-    servePackages((builder) => builder.serve("foo", "1.2.3"));
-
-    d.appDir({
-      "foo": "1.2.3"
-    }).create();
-
-    pubGet();
-
-    d.cacheDir({
-      "foo": "1.2.3"
-    }).validate();
-    d.packagesDir({
-      "foo": "1.2.3"
-    }).validate();
-  });
-
-  integration('URL encodes the package name', () {
-    serveNoPackages();
-
-    d.appDir({
-      "bad name!": "1.2.3"
-    }).create();
-
-    pubGet(
-        error: new RegExp(
-            r"Could not find package bad name! at http://localhost:\d+\."),
-        exitCode: exit_codes.UNAVAILABLE);
-  });
-}