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

frog/tests/frog_native/native_null_frog_test.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.
-
-// Test that parameters in native methods are not mangled. This test is needed
-// until we change all libraries to using the JS foreign element.
-
-class A native "*A" {
-  returnNull() native "return null;";
-  returnUndefined() native "return undefined;";
-  returnEmptyString() native "return '';";
-  returnZero() native "return 0;";
-}
-
-A makeA() native;
-
-void setup() native """
-function A() {}
-makeA = function(){return new A;};
-""";
-
-
-main() {
-  setup();
-  A a = makeA();
-  Expect.equals(null, a.returnNull());
-  Expect.equals(null, a.returnUndefined());
-
-  Expect.equals('', a.returnEmptyString());
-  Expect.isTrue(a.returnEmptyString().isEmpty());
-  Expect.isTrue(a.returnEmptyString() is String);
-
-  Expect.isTrue(a.returnZero() is int);
-  Expect.equals(0, a.returnZero());
-}