Move frog/tests/{leg,leg_only,frog_native} to tests/compiler/.

frog/tests/frog_native/native_window1_frog_test.dart

-// 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.
-
-interface Window {
-  final int document;
-}
-
-// Defining this global object makes Frog eager on optimizing
-// call sites where the receiver is typed 'Window'.
-class _DOMWindowJs implements Window native "@*DOMWindow" {
-  final int document;
-}
-
-class Win implements Window {
-}
-
-main() {
-  // By typing this variable to 'Window', Frog will optimize calls on
-  // it.
-  Window win = new Win();
-  Expect.throws(() => win.document,
-                (e) => e is NoSuchMethodException);
-}