[frames] Also properly deal with TF builtins in OptimizedFrame::GetFunctions().

test/mjsunit/regress/regress-crbug-599714.js

Index: test/mjsunit/regress/regress-crbug-599714.js
diff --git a/test/mjsunit/regress/regress-crbug-599714.js b/test/mjsunit/regress/regress-crbug-599714.js
new file mode 100644
index 0000000000000000000000000000000000000000..98de3406b7925a0ed4b77c4f66dca5f8b411c35d
--- /dev/null
+++ b/test/mjsunit/regress/regress-crbug-599714.js
@@ -0,0 +1,13 @@
+// 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.
+
+var custom_toString = function() {
+  var boom = custom_toString.caller;
+  return boom;
+}
+
+var object = {};
+object.toString = custom_toString;
+
+try { Object.hasOwnProperty(object); } catch (e) {}