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

frog/tests/frog_native/native_library_same_name_used_lib1.dart

-// 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.
-
-// 'I' is the name of an interface and the name of the native class.
-
-#library('native_library_same_name_used_lib1.dart');
-
-#import('native_library_same_name_used_lib2.dart');
-
-interface I {
-  I read();
-  write(I x);
-}
-
-makeI() native { new Impl(); }  // Hint Impl is created by makeI.