Fix warnings_checker.dart handling of multitests

tests/lib/mirrors/redirecting_factory_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 "dart:mirrors";
 import "package:expect/expect.dart";
 import "stringify.dart";
 
 class Class<T1, T2> {
   final field;
@@ skipping 25 matching lines @@
   }
 
   factory Class.redirectingFactoryMoreUnnamedOptional(a, [b]) =
       Class.factoryMoreUnnamedOptional;
 
   factory Class.redirectingFactoryStringIntTypeParameters(a, b) =
       Class<String, int>.factoryNoOptional;
 
   factory Class.redirectingFactoryStringTypeParameters(a, b) =
       Class
-        <String> // /// 02: static type warning
+        <String> // //# 02: static type warning
       .factoryNoOptional;
 
   factory Class.redirectingFactoryTypeParameters(a, b) =
       Class<T1, T2>.factoryNoOptional;
 
   factory Class.redirectingFactoryReversedTypeParameters(a, b) =
       Class<T2, T1>.factoryNoOptional;
 }
 
 main() {
@@ skipping 21 matching lines @@
   Expect.isFalse(instanceMirror.reflectee is Class<int, String>);
 
   instanceMirror = classMirror.newInstance(
       #redirectingFactoryStringTypeParameters, [43, 1]);
   Expect.equals(42, instanceMirror.reflectee.field);
   Expect.isTrue(instanceMirror.reflectee is Class<String, int>);
   Expect.isTrue(instanceMirror.reflectee is Class<String, String>);
   Expect.isTrue(instanceMirror.reflectee is Class<int, String>);
 
   bool isDart2js = false;
-  isDart2js = true; /// 01: ok
+  isDart2js = true; //# 01: ok
   if (isDart2js) return;
 
   instanceMirror = classMirror.newInstance(
       #redirectingFactoryUnnamedOptional, [43]);
   Expect.equals(1, instanceMirror.reflectee.field);
 
   instanceMirror = classMirror.newInstance(
       #redirectingFactoryNamedOptional, [43]);
   Expect.equals(1, instanceMirror.reflectee.field);
 
@@ skipping 16 matching lines @@
   Expect.isTrue(instanceMirror.reflectee is Class<String, int>);
   Expect.isFalse(instanceMirror.reflectee is Class<int, String>);
 
   instanceMirror = classMirror.newInstance(
       #redirectingFactoryReversedTypeParameters, [43, 1]);
   Expect.equals(42, instanceMirror.reflectee.field);
   Expect.isTrue(instanceMirror.reflectee is Class<int, String>);
   Expect.isFalse(instanceMirror.reflectee is Class<String, int>);
 }