dart:io | Revert addition of Link class, because it conflicts with a Link class in dart2js.

runtime/bin/file_win.cc

Index: runtime/bin/file_win.cc
diff --git a/runtime/bin/file_win.cc b/runtime/bin/file_win.cc
index 2d6dae865db706d09dbabf84c8f6cf2acb72916b..1c22ededcf24a42cf4e9f11b88c82581a71948d3 100644
--- a/runtime/bin/file_win.cc
+++ b/runtime/bin/file_win.cc
@@ -154,12 +154,6 @@ bool File::Create(const char* name) {
 }
 
 
-bool File::CreateLink(const char* name, const char* target) {
-  // TODO(whesse): Implement Junction creation.
-  return false;
-}
-
-
 bool File::Delete(const char* name) {
   const wchar_t* system_name = StringUtils::Utf8ToWide(name);
   int status = _wremove(system_name);