Clean up isolate tests.

tests/isolate/isolate3_negative_test.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.
-
-// Dart test program for testing that errors thrown from isolates are
-// processed correctly and don't result in crashes.
-
-library Isolate3NegativeTest;
-import 'dart:isolate';
-import '../../pkg/unittest/lib/unittest.dart';
-
-class TestClass {
-  TestClass.named(num this.fld1) : fld2=fld1 {
-    TestClass.i = 0;  // Should cause a compilation error.
-  }
-  num fld1;
-  num fld2;
-}
-
-void entry(SendPort replyTo) {
-  var tmp = new TestClass.named(10);
-  replyTo.send(tmp);
-}
-
-main() {
-  test("child isolate compilation errors propagate correctly. ", () {
-    void msg_callback(var message) {
-      // This test is a negative test and should not complete successfully.
-    }
-    ReceivePort response = new ReceivePort();
-    Isolate.spawn(entry, response.sendPort);
-    response.first.then(expectAsync1(msg_callback));
-  });
-}