Move test to dart2js_extra since it does not apply to VM.

tests/language/bailout8_test.dart

-// Copyright (c) 2013, 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";
-
-var a;
-var b;
-
-bar() {
-  a = a == null ? 42 : new Object();
-  a += b;
-}
-
-foo() {
-  a = a == null ? new Object() : 42;
-  a--;
-}
-
-main() {
-  for (int i = 0; i < 10; i++) {
-    a = null;
-    Expect.throws(foo, (e) => e is NoSuchMethodError);
-    a = null;
-    Expect.throws(bar, (e) => e is ArgumentError);
-  }
-}