Import rasta tests.

pkg/fasta/test/rasta/issue_000068.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.
+
+import "package:expect/expect.dart";
+
+class G<T> {}
+
+class A {}
+class B extends A {}
+class C extends B {}
+
+main() {
+  Expect.isFalse(new G<B>() is G<C>);
+  Expect.isFalse(new G<A>() is G<B>);
+  Expect.isFalse(new G<A>() is G<C>);
+  Expect.isFalse(new G<Object>() is G<B>);
+  Expect.isFalse(new G<int>() is G<B>);
+  Expect.isFalse(new G<int>() is G<double>);
+  Expect.isFalse(new G<int>() is G<String>);
+}