Migrate test block 7 to Dart 2.0.

tests/corelib_strong/error_stack_trace2_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";
-
-class A {
-  get foo => cyclicStatic;
-}
-
-var a = new A();
-dynamic cyclicStatic = (() => a.foo + 1)();
-
-cyclicInitialization() {
-  return cyclicStatic;
-}
-
-main() {
-  bool hasThrown = false;
-  try {
-    cyclicStatic + 1;
-  } catch (e2) {
-    var e = e2;
-    hasThrown = true;
-    Expect.isTrue(
-        e.stackTrace is StackTrace, "$e doesn't have a non-null stack trace");
-  }
-  Expect.isTrue(hasThrown);
-}