src/third_party/mozjs-45/js/src/jit-test/tests/jaeger/bug576398.js

function K(x) {
  with ({});    // prevent compilation
  this.x = x; 
}
function f() {
  var a = new K(1);
  var b = new K(2);
  return (a == b);
}
assertEq(f(), false);