message: Use edition flag for 2phase test
  The compiler now rejects one of the examples with #![feature(nll)]
diff: -#![feature(nll)]
  +// edition:2018
  trait S: Sized {
  fn tpb(&mut self, _s: Self) {}
  @@ -54,6 +54,8 @@ fn with_interior_mutability() {
  let mut x = Cell::new(1);
  let l = &x;
  +
  + #[allow(unknown_lints, mutable_borrow_reservation_conflict)]
  x
  .do_the_thing({
  x.set(3);
  