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

frog/tests/leg/parameter_phi_elimination_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.
-
-// Regression test. Failed due to trying to detach an HLocal twice.
-
-// VMOptions=--enable_asserts
-
-#import("compiler_helper.dart");
-
-final String SOURCE = @"""
-bool baz(int a, int b) {
-  while (a == b || a < b) {
-    a = a + b;
-  }
-  return a == b;
-}
-""";
-
-
-main() {
-  compile(SOURCE, "baz");
-}