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

sdk/lib/_internal/pub_generated/test/serve/does_not_serve_dart_in_release_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 file.
 
 library pub_tests;
 
 import '../descriptor.dart' as d;
 import '../test_pub.dart';
 import 'utils.dart';
 
 main() {
   initConfig();
   integration("does not serve .dart files in release mode", () {
 
-    d.dir("foo", [
-      d.libPubspec("foo", "0.0.1"),
-      d.dir("lib", [
-        d.file("foo.dart",
-            """
+    d.dir(
+        "foo",
+        [d.libPubspec("foo", "0.0.1"), d.dir("lib", [d.file("foo.dart", """
             library foo;
             foo() => 'foo';
-            """)
-      ])
-    ]).create();
+            """)])]).create();
 
-    d.dir(appPath, [
-      d.appPubspec({
-        "foo": {"path": "../foo"}
+    d.dir(appPath, [d.appPubspec({
+        "foo": {
+          "path": "../foo"
+        }
       }),
-      d.dir("lib", [
-        d.file("lib.dart", "lib() => print('hello');"),
-      ]),
-      d.dir("web", [
-        d.file("file.dart",
-            """
+          d.dir("lib", [d.file("lib.dart", "lib() => print('hello');"),]),
+          d.dir("web", [d.file("file.dart", """
             import 'package:foo/foo.dart';
             main() => print('hello');
             """),
-        d.dir("sub", [
-          d.file("sub.dart", "main() => 'foo';"),
-        ])
-      ])
-    ]).create();
+            d.dir("sub", [d.file("sub.dart", "main() => 'foo';"),])])]).create();
 
     pubServe(shouldGetFirst: true, args: ["--mode", "release"]);
     requestShould404("file.dart");
     requestShould404("packages/myapp/lib.dart");
     requestShould404("packages/foo/foo.dart");
     requestShould404("sub/sub.dart");
     endPubServe();
   });
 }