Migrate block 114 (and some of 113).

tests/language_2/generic_methods_shadowing_test.dart

 // Copyright (c) 2017, 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.
 
 // Test that type parameters in generic methods can be shadowed.
 
 library generic_methods_shadowing_test;
 
 import "package:expect/expect.dart";
 
 class X {}
 
 class Y {}
 
 bool foo<T, S>(T t, S s) {
   // The type parameter T of bar shadows the type parameter T of foo.
   bool bar<T>(T t) {
     return t is T && t is S;
   }
 
   return bar<S>(s);
 }
 
 main() {
   Expect.isTrue(foo<X, Y>(new X(), new Y()));
 }