message: fix compile-fail test
diff: -use std::mem;
  -
  fn main() {
  let b = Box::new(0);
  let x = &*b as *const i32;
  // We cannot compare this with a non-NULL integer. After all, these *could* be equal (with the right base address).
  - assert!(x != mem::align_of::<i32>() as *const i32); //~ ERROR invalid arithmetic on pointers
  + assert!(x != 64 as *const i32); //~ ERROR invalid arithmetic on pointers
  }
  