Use microtasks in dart.async

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 56 matching lines @@
 
       // TODO(vsm): Re-enable (https://github.com/dart-lang/sdk/issues/28319)
       'async_star_test_none_multi': async_unittest,
       'async_star_test_01_multi': async_unittest,
       'async_star_test_02_multi': async_unittest,
       'async_star_test_03_multi': async_unittest,
       'async_star_test_04_multi': async_unittest,
       'async_star_test_05_multi': async_unittest,
 
       'async_switch_test': fail,
-      'asyncstar_throw_in_catch_test': fail,
+      'asyncstar_throw_in_catch_test': ['skip', 'fail'],
       'await_future_test': skip_timeout,
       'bit_operations_test_none_multi': fail,  // DDC/dart2js canonicalize bitop results to unsigned
       'branch_canonicalization_test': fail,  // JS bit operations truncate to 32 bits.
       'call_closurization_test': fail, // Functions do not expose a "call" method.
       'call_function_apply_test': fail, // Function.apply not really implemented.
       'call_through_null_getter_test': fail, // null errors are not converted to NoSuchMethodErrors.
       'call_with_no_such_method_test': fail, // Function.apply not really implemented.
       'canonical_const2_test': fail,
       'canonical_const_test': fail,
       'cast_test_01_multi': fail,
@@ skipping 790 matching lines @@
 
     for (let action of unittest_tests) {
       try {
         action();
       } catch (e) {
         console.error("Caught error tying to setup test:", e);
       }
     }
   });
 });