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

sdk/lib/_internal/pub_generated/test/get/path/relative_symlink_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 'dart:io';
 
 import 'package:path/path.dart' as path;
 
 import '../../descriptor.dart' as d;
 import '../../test_pub.dart';
 
 main() {
   // Pub uses NTFS junction points to create links in the packages directory.
   // These (unlike the symlinks that are supported in Vista and later) do not
   // support relative paths. So this test, by design, will not pass on Windows.
   // So just skip it.
   if (Platform.operatingSystem == "windows") return;
 
   initConfig();
-  integration("generates a symlink with a relative path if the dependency "
-              "path was relative", () {
-    d.dir("foo", [
-      d.libDir("foo"),
-      d.libPubspec("foo", "0.0.1")
-    ]).create();
+  integration(
+      "generates a symlink with a relative path if the dependency "
+          "path was relative",
+      () {
+    d.dir("foo", [d.libDir("foo"), d.libPubspec("foo", "0.0.1")]).create();
 
-    d.dir(appPath, [
-      d.appPubspec({
-        "foo": {"path": "../foo"}
-      })
-    ]).create();
+    d.dir(appPath, [d.appPubspec({
+        "foo": {
+          "path": "../foo"
+        }
+      })]).create();
 
     pubGet();
 
     d.dir("moved").create();
 
     // Move the app and package. Since they are still next to each other, it
     // should still be found.
     scheduleRename("foo", path.join("moved", "foo"));
     scheduleRename(appPath, path.join("moved", appPath));
 
-    d.dir("moved", [
-      d.dir(packagesPath, [
-        d.dir("foo", [
-          d.file("foo.dart", 'main() => "foo";')
-        ])
-      ])
-    ]).validate();
+    d.dir(
+        "moved",
+        [
+            d.dir(
+                packagesPath,
+                [d.dir("foo", [d.file("foo.dart", 'main() => "foo";')])])]).validate();
   });
 }