Fix warnings_checker.dart handling of multitests

tests/language_strong/const_dynamic_type_literal_test.dart

 // Copyright (c) 2015, 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 'dynamic' can be used in const expressions and has the expected
 // behavior.
 
 import "package:expect/expect.dart";
 
 const d = dynamic;
 const i = int;
 
 void main() {
-  Expect.isTrue(identical(d, dynamic)); /// 01: ok
-  Expect.equals(1, const { d: 1, d: 2 }.length); /// 02: static type warning
-  Expect.equals(2, const { d: 1, i: 2 }.length); /// 03: ok
+  Expect.isTrue(identical(d, dynamic)); //# 01: ok
+  Expect.equals(1, const { d: 1, d: 2 }.length); //# 02: static type warning
+  Expect.equals(2, const { d: 1, i: 2 }.length); //# 03: ok
 }