Improve the capture and display of syntax errors in VM tests.

test/frontend/expect_async_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.
 
 import 'dart:async';
 
 import 'package:test/src/backend/state.dart';
 import 'package:test/test.dart';
 
 import '../utils.dart';
 
 void main() {
-  group("supports a function with this many arguments:", () {

[kevmoo, 2015/06/10 14:24:10]

Oops?

[nweiz, 2015/06/10 21:22:01]

Done.

+  group("supports a function with this many arguments:", ()
     test("0", () async {
       var callbackRun = false;
       var liveTest = await runTestBody(() {
         expectAsync(() {
           callbackRun = true;
         })();
       });
 
       expectTestPassed(liveTest);
       expect(callbackRun, isTrue);
@@ skipping 299 matching lines @@
           caughtError = true;
         }
       });
 
       expectTestFailed(liveTest, 'oh no');
       expect(returnValue, isNull);
       expect(caughtError, isFalse);
     });
   });
 }