Fix warnings_checker.dart handling of multitests

tests/language/super_no_such_method3_test.dart

 // Copyright (c) 2016, 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';
 
 var result;
 
 class A {
   noSuchMethod(im) {
     result = 42;
   }
 }
 
 class B extends A {
   noSuchMethod(im) {
     result = 87;
   }
 
-  set foo(v) => super.foo = v; /// 01: static type warning
+  set foo(v) => super.foo = v; //# 01: static type warning
 }
 
 main() {
-  new B().foo = 0; //          /// 01: continued
-  Expect.equals(42, result); /// 01: continued
+  new B().foo = 0; //          //# 01: continued
+  Expect.equals(42, result); //# 01: continued
 }