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

sdk/lib/_internal/pub_generated/test/build/handles_long_paths_test.dart

-// Copyright (c) 2013, 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.
-
-import 'package:scheduled_test/scheduled_test.dart';
-
-import 'package:path/path.dart' as path;
-
-import '../descriptor.dart' as d;
-import '../test_pub.dart';
-
-main() {
-  initConfig();
-
-  // This is a regression test for dartbug.com/14442.
-  //
-  // If you have a long chain of path dependencies with long relative paths,
-  // you can end up with a combined path that is longer than the OS can handle.
-  // For example, the path that revealed this bug was:
-  //
-  // C:\jenkins-slave\workspace\mSEE-Dev\ozone\dart\portfolio-manager\src\main\
-  // portfolio-manager\..\..\..\..\portfolio-common\src\main\portfolio-common\
-  // ../../../../dart-visualization/src/main/dart-visualization\lib\src\vega\
-  // data\transform\visual
-  //
-  // This test ensures that we're normalizing at some point before we throw the
-  // path at the OS to choke on.
-
-  integration("handles long relative paths", () {
-    // Dart2js can take a long time to compile dart code, so we increase the
-    // timeout to cope with that.
-    currentSchedule.timeout *= 3;
-
-    d.dir(
-        "some_long_dependency_name",
-        [
-            d.libPubspec("foo", "0.0.1"),
-            d.dir("lib", [d.file("foo.txt", "foo")])]).create();
-
-    // Build a 2,800 character (non-canonicalized) path.
-    var longPath = "";
-    for (var i = 0; i < 100; i++) {
-      longPath = path.join(longPath, "..", "some_long_dependency_name");
-    }
-
-    d.dir(appPath, [d.appPubspec({
-        "foo": {
-          "path": longPath
-        }
-      }), d.dir("web", [d.file("index.html", "html"),])]).create();
-
-    schedulePub(
-        args: ["build"],
-        output: new RegExp(r'Built 2 files to "build".'));
-
-    d.dir(
-        appPath,
-        [
-            d.dir(
-                'build',
-                [
-                    d.dir(
-                        'web',
-                        [
-                            d.file("index.html", "html"),
-                            d.dir('packages', [d.dir('foo', [d.file('foo.txt', 'foo')])])])])]).validate();
-  });
-}