diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/bug764289.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/bug764289.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,3 @@
+// Don't crash. May require valgrind.
+var prox = Proxy.create({getPropertyDescriptor: function() { }});
+Object.prototype.__lookupGetter__.call(prox, 'q');