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

sdk/lib/_internal/pub_generated/test/get/relative_symlink_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 'dart:io';
 
 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('uses a relative symlink for the self link', () {
-    d.dir(appPath, [
-      d.appPubspec(),
-      d.libDir('foo')
-    ]).create();
+    d.dir(appPath, [d.appPubspec(), d.libDir('foo')]).create();
 
     pubGet();
 
     scheduleRename(appPath, "moved");
 
-    d.dir("moved", [
-      d.dir("packages", [
-        d.dir("myapp", [
-          d.file('foo.dart', 'main() => "foo";')
-        ])
-      ])
-    ]).validate();
+    d.dir(
+        "moved",
+        [
+            d.dir(
+                "packages",
+                [d.dir("myapp", [d.file('foo.dart', 'main() => "foo";')])])]).validate();
   });
 
   integration('uses a relative symlink for secondary packages directory', () {
-    d.dir(appPath, [
-      d.appPubspec(),
-      d.libDir('foo'),
-      d.dir("bin")
-    ]).create();
+    d.dir(appPath, [d.appPubspec(), d.libDir('foo'), d.dir("bin")]).create();
 
     pubGet();
 
     scheduleRename(appPath, "moved");
 
-    d.dir("moved", [
-      d.dir("bin", [
-        d.dir("packages", [
-          d.dir("myapp", [
-            d.file('foo.dart', 'main() => "foo";')
-          ])
-        ])
-      ])
-    ]).validate();
+    d.dir(
+        "moved",
+        [
+            d.dir(
+                "bin",
+                [
+                    d.dir(
+                        "packages",
+                        [d.dir("myapp", [d.file('foo.dart', 'main() => "foo";')])])])]).validate();
   });
 }