Properly support `ioctl` that takes the last argument as an integer not a pointer about rustix HOT 2 OPEN

During my design of this trait the intention was to involve an int-to-pointer cast here. Those are relatively rare in the ecosystem, so it should be somewhat awkward to use as a way of making sure that's what you really want.

Although, if it's common I think it would be good to add something similar to rustix::ioctl::Setter that does a number instead of a pointer.

from rustix.

The issue is not whether it's rare, but that for these ioctls passing values directly are the only way to communicate with the kernel. If you want to use TUNSETOFFLOAD with rustix the only way is to define that UintSetter somewhere, there are no workarounds. And I prefer that type to be placed in rustix itself rather than my crate 😉

from rustix.