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

sdk/lib/_internal/pub_generated/test/upgrade/hosted/upgrade_removed_constraints_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 '../../descriptor.dart' as d;
 import '../../test_pub.dart';
 
 main() {
   initConfig();
   integration("upgrades dependencies whose constraints have been removed", () {
     servePackages((builder) {
-      builder.serve("foo", "1.0.0", deps: {"shared-dep": "any"});
-      builder.serve("bar", "1.0.0", deps: {"shared-dep": "<2.0.0"});
+      builder.serve("foo", "1.0.0", deps: {
+        "shared-dep": "any"
+      });
+      builder.serve("bar", "1.0.0", deps: {
+        "shared-dep": "<2.0.0"
+      });
       builder.serve("shared-dep", "1.0.0");
       builder.serve("shared-dep", "2.0.0");
     });
 
-    d.appDir({"foo": "any", "bar": "any"}).create();
+    d.appDir({
+      "foo": "any",
+      "bar": "any"
+    }).create();
 
     pubUpgrade();
 
     d.packagesDir({
       "foo": "1.0.0",
       "bar": "1.0.0",
       "shared-dep": "1.0.0"
     }).validate();
 
-    d.appDir({"foo": "any"}).create();
+    d.appDir({
+      "foo": "any"
+    }).create();
 
     pubUpgrade();
 
     d.packagesDir({
       "foo": "1.0.0",
       "bar": null,
       "shared-dep": "2.0.0"
     }).validate();
   });
 }