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

sdk/lib/_internal/pub_generated/test/global/deactivate/removes_precompiled_snapshots_test.dart

 // Copyright (c) 2014, 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 '../../descriptor.dart' as d;
 import '../../test_pub.dart';
 
 main() {
   initConfig();
   integration('removes precompiled snapshots', () {
     servePackages((builder) => builder.serve("foo", "1.0.0"));
 
     schedulePub(args: ["global", "activate", "foo"]);
 
-    schedulePub(args: ["global", "deactivate", "foo"],
+    schedulePub(
+        args: ["global", "deactivate", "foo"],
         output: "Deactivated package foo 1.0.0.");
 
-    d.dir(cachePath, [
-      d.dir('global_packages', [d.nothing('foo')])
-    ]).validate();
+    d.dir(cachePath, [d.dir('global_packages', [d.nothing('foo')])]).validate();
   });
 }