Fix infinite recursion when dealing with cyclic library dependencies.

bin/file_win.cc

 // 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.
 
 #include <fcntl.h>
 #include <io.h>
 #include <stdio.h>
 #include <string.h>
 #include <sys/stat.h>
 
@@ skipping 102 matching lines @@
 
 bool File::IsAbsolutePath(const char* pathname) {
   // Should we consider network paths?
   if (pathname == NULL) return false;
   return (strlen(pathname) > 2) &&
       (pathname[1] == ':') &&
       (pathname[2] == '\\');
 }
 
 
+char* File::GetCanonicalPath(const char* pathname) {
+  UNIMPLEMENTED();
+  return pathname;
+}
+
+
 const char* File::PathSeparator() {
   return "\\";
 }
 
 
 const char* File::StringEscapedPathSeparator() {
   return "\\\\";
 }