message: fix a Stacked Borrows test whose output changed
diff: @@ -3,6 +3,6 @@ static X: usize = 5;
  #[allow(mutable_transmutes)]
  fn main() {
  let _x = unsafe {
  - std::mem::transmute::<&usize, &mut usize>(&X) //~ ERROR borrow stack
  + std::mem::transmute::<&usize, &mut usize>(&X) //~ ERROR writing to alloc0 which is read-only
  };
  }
  