lingering step 2 of the test rename overhaul: make await tests also a directory

frog/tests/await/test_config.dart

-// Copyright (c) 2011, 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("await_test_config");
-
-#import("../../../tools/testing/dart/test_suite.dart");
-
-class AwaitTestSuite extends StandardTestSuite {
-  AwaitTestSuite(Map configuration)
-      : super(configuration,
-              "await",
-              "frog/tests/await",
-              ["frog/tests/await/await.status"]);
-
-  List<String> additionalOptions(String filename) {
-    return ['$dartDir/frog/await/awaitc.dart'];
-  }
-
-  bool isTestFile(String filename) => filename.endsWith("_test.dart");
-}