dart2js: run dartfmt on tests

tests/compiler/dart2js_extra/regress/4562_test.dart

 // Copyright (c) 2012, 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.
 
 void main() {
   var foo = new Foo();
-  var bar = new Bar(); /// 01: compile-time error
+  var bar = new Bar();
+
+  /// 01: compile-time error

[Siggi Cherem (dart-lang), 2016/09/16 20:55:22]

revert

[Harry Terkelsen, 2016/09/16 21:44:03]

Done.

 }
 
 class Foo {
   factory Foo() => null;
 }
 
 class Bar extends Foo {
-  Bar(); /// 01: continued
+  Bar();
+
+  /// 01: continued
 }