Fix warnings_checker.dart handling of multitests

tests/language_strong/static_getter_no_setter2_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 'package:expect/expect.dart';
 
 class Class {
   static int get getter => 0;
 
   method() {
     try {
-      getter++; /// 01: static type warning
+      getter++; //# 01: static type warning
     } on NoSuchMethodError catch(e) {
       return;
     }
-    Expect.fail('Expected NoSuchMethodError'); /// 01: continued
+    Expect.fail('Expected NoSuchMethodError'); //# 01: continued
   }
 
   noSuchMethod(i) {
     return 42;
   }
 }
 
 class Subclass extends Class {
   method() {
-    print(getter); /// 01: continued
+    print(getter); //# 01: continued
     super.method();
   }
 }
 
 main() {
   new Subclass().method();
 }