Recently stabilised Waker::data()

[midnightveil]

Hi, was reading your code as a nice little reference, and I think the extract_mask() function of exec.rs could be replaced with the 1.83 stabilisation of Waker::data().

https://github.com/cbiffle/lilos/blob/7fc6c6469a0407bf6c8e543444aed5b4237774bb/os/src/exec.rs#L203-L246

https://dev-doc.rust-lang.org/std/task/struct.Waker.html#method.data

Possibly not 100% desired since it's quite new, but it'd be nice to use if possible. (unfortunately, cfg-version gating seems to still be nightly only...)