Migrate test block 113 to Dart 2.0.

tests/language_2/generic_function_dcall_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.
 
 import 'package:expect/expect.dart';
 
 void testCallsToGenericFn() {
   T f<T>(T a, T b) => ((a as dynamic) + b) as T;
 
   var x = (f as dynamic)<int>(40, 2);
@@ skipping 39 matching lines @@
   // to change this in DDC at some point.
   Expect.equals(f.runtimeType.toString(), "<T>(T) -> T");
 }
 
 main() {
   testCallsToGenericFn();
   testGenericFnAsArg();
   testGenericFnAsGenericFnArg();
   testGenericFnTypeToString();
 }