Fix warnings_checker.dart handling of multitests

tests/corelib/list_test.dart

 // Copyright (c) 2011, 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:collection";
 import "dart:typed_data";
 import "package:expect/expect.dart";
 
 void main() {
   // Typed lists - fixed length and can only contain integers.
@@ skipping 564 matching lines @@
   List<E> _source;
   MyFixedList(this._source);
   int get length => _source.length;
   void set length(int length) { throw new UnsupportedError("Fixed length!"); }
   E operator[](int index) => _source[index];
   void operator[]=(int index, E value) { _source[index] = value; }
 }
 
 void testListConstructor() {
   Expect.throws(() { new List(0).add(4); });  // Is fixed-length.
-  Expect.throws(() { new List(-2); });  // Not negative. /// 01: ok
+  Expect.throws(() { new List(-2); });  // Not negative. //# 01: ok
   Expect.throws(() { new List(null); });  // Not null.
   Expect.listEquals([4], new List()..add(4));
   Expect.throws(() { new List.filled(0, 42).add(4); });  // Is fixed-length.
   Expect.throws(() { new List.filled(-2, 42); });  // Not negative.
   Expect.throws(() { new List.filled(null, 42); });  // Not null.
 }