Fix warnings_checker.dart handling of multitests

tests/language_strong/malformed2_test.dart

 // Copyright (c) 2013, 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.
 
 library malformed_test;
 
 // This part includes the actual tests.
-part 'malformed2_lib.dart'; /// 00: static type warning
+part 'malformed2_lib.dart'; //# 00: static type warning
 
 bool inCheckedMode() {
   try {
     var i = 42;
     String s = i;
   } on TypeError catch (e) {
     return true;
   }
   return false;
 }
@@ skipping 23 matching lines @@
     }
   } on TypeError catch (e) {
     if (expectTypeError) {
       print('Type error$message: $e');
     } else {
       fail('Unexpected type error$message: $e');
     }
   }
 }
 
-const Unresolved c1 = 0; /// 01: static type warning, checked mode compile-time error
+const Unresolved c1 = 0; //# 01: static type warning, checked mode compile-time error
 
 void main() {
-  print(c1); /// 01: continued
-  testValue(new List<String>()); /// 00: continued
-  testValue(null); /// 00: continued
+  print(c1); //# 01: continued
+  testValue(new List<String>()); //# 00: continued
+  testValue(null); //# 00: continued
   checkFailures();
 }