src/third_party/mozjs-45/js/src/jit-test/tests/basic/bug560234b.js

function f(a) {
   function g() {
       yield function () a;
   }
   if (a == 8)
       return g();
   a = 3;
}
var x;
for (var i = 0; i < 9; i++)
   x = f(i);
x.next()();  // ReferenceError: a is not defined.