Add test of unittests.

tests/compiler/dart2js/js_backend_cps_ir_gvn_test.dart

 // Copyright (c) 2015, 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 the GVN optimization pass works as expected.
 
-library basic_tests;
+library gvn_tests;
 
 import 'js_backend_cps_ir.dart';
 
 const List<TestEntry> tests = const [
   const TestEntry(r"""
 foo(x, list) {
   var sum = 0;
   for (int k = 0; k < 10; k++) {
     // Everything can be hoisted out up to the index access which is
     // blocked by the bounds check.
@@ skipping 50 matching lines @@
     if (!(typeof print == "function"))
       throw "Unable to print message: " + String(v0);
     print(v0);
   }
 }"""),
 ];
 
 void main() {
   runTests(tests);
 }