Fix warnings_checker.dart handling of multitests

tests/language_strong/fixed_type_variable_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.
 
 // Test that type variables are passed on from subtypes that fixed the type
 // variable in inheritance.
 
 import 'package:expect/expect.dart';
 
 class A<T> {
@@ skipping 14 matching lines @@
 class StringB extends B<String> {
 }
 
 class C<T> extends A<T> {
 }
 
 class IntC extends C<int> {
 }
 
 void main() {
-  testA(); /// 01: ok
-  testNumA(); /// 02: ok
-  testB(); /// 03: ok
-  testStringB(); /// 04: ok
-  testC(); /// 05: ok
-  testIntC(); /// 06: ok
+  testA(); //# 01: ok
+  testNumA(); //# 02: ok
+  testB(); //# 03: ok
+  testStringB(); //# 04: ok
+  testC(); //# 05: ok
+  testIntC(); //# 06: ok
 }
 
 void testA() {
   var instanceA = new A<String>();
   var instanceB = instanceA.createB();
   instanceB.test(num, false);
   instanceB.test(int, false);
   instanceB.test(String, true);
 }
 
@@ skipping 27 matching lines @@
   instanceB.test(String, true);
 }
 
 void testIntC() {
   var instanceA = new IntC();
   var instanceB = instanceA.createB();
   instanceB.test(num, false);
   instanceB.test(int, true);
   instanceB.test(String, false);
 }