Add all dart:html tests from the sdk to test/codegen.

test/codegen/lib/html/non_instantiated_is_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.
+
+// Regression test for dart2js, that used to emit wrong code on is
+// checks of native classes that are not instantiated.
+
+import 'dart:html';
+import 'package:unittest/unittest.dart';
+import 'package:unittest/html_config.dart';
+
+var a = [new Object()];
+
+main() {
+  useHtmlConfiguration();
+
+  test('is', () {
+    expect(a[0] is Node, isFalse);
+  });
+}