remove promise from corelib

tests/stub-generator/test_config.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("stub_generator_test_config");
-
-#import("../../tools/testing/dart/test_suite.dart");
-
-class StubGeneratorTestSuite extends StandardTestSuite {
-  StubGeneratorTestSuite(Map configuration)
-      : super(configuration,
-              "stub-generator",
-              "tests/stub-generator/src",
-              ["tests/stub-generator/stub-generator.status"]);
-
-  bool isTestFile(String filename) => filename.endsWith("-generatedTest.dart");
-}