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

frog/tests/leg/no_constructor_body_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.
-
-#import("compiler_helper.dart");
-
-final String TEST = @"""
-class A {
-  A.foo() {}
-  A();
-}
-main() {
-  new A();
-  new A.foo();
-}
-""";
-
-main() {
-  String generated = compileAll(TEST);
-  Expect.isTrue(generated.contains('\$.A = {"":\n [],\n super: "Object"\n};'));
-}