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

frog/tests/leg_only/closure_capture3_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.
-
-class Closure {
-  var x;
-  Closure(val) : this.x = val;
-
-  foo() {
-    return fun() {
-      return x;
-    };
-  }
-
-  bar() {
-    return fun() {
-      return toto();
-    };
-  }
-
-  toto() {
-    return x + 1;
-  }
-
-  nestedClosure() {
-    var f = g() { return x; };
-    return fun() { return f() + 2; };
-  }
-}
-
-main() {
-  var c = new Closure(499);
-  var f = c.foo();
-  Expect.equals(499, f());
-  Expect.equals(500, c.bar()());
-  Expect.equals(501, c.nestedClosure()());
-}