Remove file name from File C++ structure. It is not used.

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 96 matching lines @@
   int fd = open(name, flags, 0666);
   if (fd < 0) {
     return NULL;
   }
   if (((mode & kWrite) != 0) && ((mode & kTruncate) == 0)) {
     int position = lseek(fd, 0, SEEK_END);
     if (position < 0) {
       return NULL;
     }
   }
-  return new File(name, new FileHandle(fd));
+  return new File(new FileHandle(fd));
 }
 
 
 File* File::OpenStdio(int fd) {
   UNREACHABLE();
   return NULL;
 }
 
 
 bool File::Exists(const char* name) {
@@ skipping 97 matching lines @@
 const char* File::StringEscapedPathSeparator() {
   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;
 }