Fix Object method tearoffs

pkg/dev_compiler/test/browser/language_tests.js

 // 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.
 
 define(['dart_sdk', 'async_helper', 'expect', 'unittest', 'is', 'require'],
       function(dart_sdk, async_helper, expect, unittest, is, require) {
   'use strict';
 
   async_helper = async_helper.async_helper;
   let minitest = expect.minitest;
@@ skipping 249 matching lines @@
       'iterable_empty_test': whitelist,
       'iterable_join_test': whitelist,
       'iterable_return_type_test_02_multi': fail,
       'json_map_test': fail,
       'list_fill_range_test': fail,
       'list_insert_all_test': whitelist,
       'list_replace_range_test': fail,
       'list_set_all_test': fail,
       'list_test_01_multi': fail,
       'list_test_none_multi': fail,
-      'list_to_string2_test': fail,
       'main_test': fail,
       'map_keys2_test': fail,
-      'map_to_string_test': fail,
       'map_from_iterable_test': is.firefox('<=50') ? fail : pass,
       'nan_infinity_test_01_multi': fail,
       'null_nosuchmethod_test': fail,
       'null_test': fail,
       'reg_exp_all_matches_test': whitelist,
       'reg_exp_start_end_test': whitelist,
       'regress_r21715_test': fail,
       'sort_test': whitelist,
       'splay_tree_from_iterable_test': is.firefox('<=50') ? fail : pass,
       'string_case_test_01_multi': firefox_fail,
@@ skipping 627 matching lines @@
 
     for (let action of unittest_tests) {
       try {
         action();
       } catch (e) {
         console.error("Caught error tying to setup test:", e);
       }
     }
   });
 });