src/third_party/mozjs-45/js/src/jit-test/tests/basic/name-inactive-eval-del.js

function mp(g) {
  ans = ''
  for (var i = 0; i < 5; ++i) {
    ans += g();
  }
  return ans;
}

var f = eval("(function() { var k = 5; function g() { return k; } k = 6; mp(g); delete k; return mp(g); })");
assertEq(f(), "66666");