diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/bug649771.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/bug649771.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,7 @@
+function f(o) {
+    f = o.constructor;
+    eval('delete o.x');
+}
+for(var i=0; i<3; i++) {
+    f(RegExp.prototype);
+}