suppose you have a function that you want to prevent an arugment from being optimized out of
```
#[no_mangle]
#[inline(never)]
fn empty_function(unused_arg : u32) {
    asm::nop();
    (&unused_ard as *const u32).read_volatile();
}
```

Is there any shorter way to do this?

not sure if black_box is equivalent or not