Reland of [compiler] Make feedback vector cope with flag changes.

test/mjsunit/regress/regress-crbug-600995.js

Index: test/mjsunit/regress/regress-crbug-600995.js
diff --git a/test/mjsunit/regress/regress-crbug-600995.js b/test/mjsunit/regress/regress-crbug-600995.js
new file mode 100644
index 0000000000000000000000000000000000000000..c532608799f59c98aa1642abdf416a9560cf2cc1
--- /dev/null
+++ b/test/mjsunit/regress/regress-crbug-600995.js
@@ -0,0 +1,10 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --noharmony-iterator-close
+
+// The {Set} function will produce a different type feedback vector layout
+// depending on whether Harmony iterator finalization is enabled or not.
+
+new Set();