Revert two Kernel changes that were causing test failures.

tests/language_2/async_break_in_finally_test.dart

-// Copyright (c) 2015, 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.
-
-import "package:expect/expect.dart";
-import "package:async_helper/async_helper.dart";
-
-then43() async {
-  label:
-  try {
-    return await 42;
-  } finally {
-    break label;
-  }
-  return await 43;
-}
-
-then42() async {
-  label:
-  try {
-    return await 42;
-  } finally {}
-  return await 43;
-}
-
-now43() {
-  label:
-  try {
-    return 42;
-  } finally {
-    break label;
-  }
-  return 43;
-}
-
-now42() {
-  label:
-  try {
-    return 42;
-  } finally {}
-  return 43;
-}
-
-test() async {
-  Expect.equals(42, await then42());
-  Expect.equals(43, await then43());
-  Expect.equals(42, now42());
-  Expect.equals(43, now43());
-}
-
-main() {
-  asyncStart();
-  test().then((_) => asyncEnd());
-}