Fix warnings_checker.dart handling of multitests

tests/language/inferrer_constructor5_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.
 
 import "package:expect/expect.dart";
 
 class A {
   A() {
-    print(field + 42); /// 01: static type warning
+    print(field + 42); //# 01: static type warning
   }
 }
 
 class B extends A {
   var field;
   B() {
     field = 42;
   }
 }
 
 main() {
-  Expect.throws(() => new B(), (e) => e is NoSuchMethodError); /// 01: continued
+  Expect.throws(() => new B(), (e) => e is NoSuchMethodError); //# 01: continued
 }