Remove erroneous assert from Windows implementation of dart:io File.fullPath.

runtime/bin/file_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 "bin/file.h"
 
 #include <fcntl.h>
 #include <io.h>
 #include <stdio.h>
 #include <string.h>
@@ skipping 191 matching lines @@
   if (stat_status != 0) {
     SetLastError(ERROR_FILE_NOT_FOUND);
     free(const_cast<wchar_t*>(system_name));
     return NULL;
   }
   int required_size = GetFullPathNameW(system_name, 0, NULL, NULL);
   wchar_t* path =
       static_cast<wchar_t*>(malloc(required_size * sizeof(wchar_t)));
   int written = GetFullPathNameW(system_name, required_size, path, NULL);
   free(const_cast<wchar_t*>(system_name));
-  ASSERT(written == (required_size - 1));
+  ASSERT(written <= (required_size - 1));
   char* result = StringUtils::WideToUtf8(path);
   free(path);
   return result;
 }
 
 
 char* File::GetContainingDirectory(char* pathname) {
   struct _stat st;
   wchar_t* system_name = StringUtils::Utf8ToWide(pathname);
   int stat_status = _wstat(system_name, &st);
@@ skipping 36 matching lines @@
   // This is already UTF-8 encoded.
   return "\\\\";
 }
 
 
 File::StdioHandleType File::GetStdioHandleType(int fd) {
   // Treat all stdio handles as pipes. The Windows event handler and
   // socket code will handle the different handle types.
   return kPipe;
 }