Really fix Windows build.

runtime/bin/directory_win.cc

 // Copyright (c) 2012, 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.
 
 #include "platform/globals.h"
 #if defined(TARGET_OS_WINDOWS)
 
 #include "bin/directory.h"
 #include "bin/file.h"
 #include "bin/utils.h"
@@ skipping 152 matching lines @@
 }
 
 ListType DirectoryListingEntry::Next(DirectoryListing* listing) {
   if (done_) {
     return kListDone;
   }
 
   WIN32_FIND_DATAW find_file_data;
 
   if (lister_ == 0) {
-    wchar_t tail = parent_ == NULL ? L"*" : L"\\*";
+    const wchar_t* tail = parent_ == NULL ? L"*" : L"\\*";
     if (!listing->path_buffer().AddW(tail)) {
       done_ = true;
       return kListError;
     }
 
     path_length_ = listing->path_buffer().length() - 1;
 
     HANDLE find_handle = FindFirstFileW(listing->path_buffer().AsStringW(),
                                         &find_file_data);
 
@@ skipping 287 matching lines @@
       MoveFileExW(system_path, system_new_path, flags);
   free(const_cast<wchar_t*>(system_path));
   free(const_cast<wchar_t*>(system_new_path));
   return (move_status != 0);
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_WINDOWS)