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

runtime/bin/file.cc

Index: runtime/bin/file.cc
diff --git a/runtime/bin/file.cc b/runtime/bin/file.cc
index f457dd97f44c6f0bc950fdb0f4017294f20177a3..a3906d33588895482ac994f44385cf280bf24b0e 100644
--- a/runtime/bin/file.cc
+++ b/runtime/bin/file.cc
@@ -425,29 +425,6 @@ void FUNCTION_NAME(File_Create)(Dart_NativeArguments args) {
 }
 
 
-void FUNCTION_NAME(File_CreateLink)(Dart_NativeArguments args) {
-  Dart_EnterScope();
-  if (Dart_IsString(Dart_GetNativeArgument(args, 0)) &&
-      Dart_IsString(Dart_GetNativeArgument(args, 1))) {
-    const char* name =
-        DartUtils::GetStringValue(Dart_GetNativeArgument(args, 0));
-    const char* target =
-        DartUtils::GetStringValue(Dart_GetNativeArgument(args, 1));
-    if (!File::CreateLink(name, target)) {
-      Dart_Handle err = DartUtils::NewDartOSError();
-      if (Dart_IsError(err)) Dart_PropagateError(err);
-      Dart_SetReturnValue(args, err);
-    }
-  } else  {
-    OSError os_error(-1, "Invalid argument", OSError::kUnknown);
-    Dart_Handle err = DartUtils::NewDartOSError(&os_error);
-    if (Dart_IsError(err)) Dart_PropagateError(err);
-    Dart_SetReturnValue(args, err);
-  }
-  Dart_ExitScope();
-}
-
-
 void FUNCTION_NAME(File_Delete)(Dart_NativeArguments args) {
   Dart_EnterScope();
   const char* str =