Fix cluster-fuzz bug introduced in refs/heads/master@{#28796}

test/mjsunit/regress/regress-crbug-501809.js

Index: test/mjsunit/regress/regress-crbug-501809.js
diff --git a/test/mjsunit/regress/regress-crbug-501809.js b/test/mjsunit/regress/regress-crbug-501809.js
new file mode 100644
index 0000000000000000000000000000000000000000..b348e5d5f6f27e3bcf6f31df0735ded1d8de4e5b
--- /dev/null
+++ b/test/mjsunit/regress/regress-crbug-501809.js
@@ -0,0 +1,9 @@
+// Copyright 2015 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: --harmony-sharedarraybuffer --harmony-atomics
+var sab = new SharedArrayBuffer(8);
+var ta = new Int32Array(sab);
+ta.__defineSetter__('length', function() {;});
+assertThrows(function() { Atomics.compareExchange(ta, 4294967295, 0, 0); });