Reland "Merge more Kernel infrastructure from kernel_sdk SDK fork."

tests/kernel/unsorted/this_test.dart

 // Copyright (c) 2016, 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.
 
-@JS()
-library js_dispatch_property_test_lib;
+import 'expect.dart';
 
-import 'package:js/js.dart';
+class A {
+  getThis() => this;
+}
 
-@JS()
-external A create();
-
-@JS() @anonymous
-class A {
-  external String foo(String x);
+main() {
+  var a = new A();
+  Expect.isTrue(a == a.getThis());
+  Expect.isTrue(identical(a, a.getThis()));
 }