Enable language and isolate tests using the dart test runner.

tools/test.dart

 #!/usr/bin/env dart_bin
 // 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("test");
 
 #import("testing/dart/test_runner.dart");
 #import("testing/dart/test_options.dart");
 
+#import("../tests/co19/test_config.dart");
+#import("../tests/corelib/test_config.dart");
+#import("../tests/isolate/test_config.dart");
+#import("../tests/language/test_config.dart");
 #import("../tests/standalone/test_config.dart");
-#import("../tests/corelib/test_config.dart");
-#import("../tests/co19/test_config.dart");
 
 // TODO(ager): This activity tracking is temporary until stdout is
 // closed implicitly when nothing more can happen.
 int pendingActivities = 0;
 
 void activityStarted() {
   ++pendingActivities;
 }
 
 void activityCompleted() {
@@ skipping 13 matching lines @@
   if (configurations == null) return;
   activityStarted();
   var queue = new ProcessQueue(configurations[0], exitIfLastActivity);
   for (var conf in configurations) {
     activityStarted();
     new StandaloneTestSuite(conf).forEachTest(queue.runTest, activityCompleted);
     activityStarted();
     new CorelibTestSuite(conf).forEachTest(queue.runTest, activityCompleted);
     activityStarted();
     new Co19TestSuite(conf).forEachTest(queue.runTest, activityCompleted);
+    activityStarted();
+    new LanguageTestSuite(conf).forEachTest(queue.runTest, activityCompleted);
+    activityStarted();
+    new IsolateTestSuite(conf).forEachTest(queue.runTest, activityCompleted);
   }
 }