Merge the work on Generic Types Reification from 'dart-lang/reify' repo

pkg/kernel/testcases/reify/subclass_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.md file.
+
+library superclass_test;
+
+import 'test_base.dart';
+
+class X {}
+
+class Y {}
+
+class R<T> {}
+
+class A<T> {
+  foo() => new R<T>();
+}
+
+class B<T> extends A<T> {}
+
+class C<T> extends A<Y> {}
+
+class D<T> extends B<R<T>> {}
+
+main() {
+  expectTrue(new A<X>().foo() is R<X>);
+  expectTrue(new B<X>().foo() is R<X>);
+  expectTrue(new C<X>().foo() is R<Y>);
+  expectTrue(new D<X>().foo() is R<R<X>>);
+
+  expectTrue(new A<X>().foo() is! R<Y>);
+  expectTrue(new B<X>().foo() is! R<Y>);
+  expectTrue(new C<X>().foo() is! R<X>);
+  expectTrue(new D<X>().foo() is! R<R<Y>>);
+}