Move unfit code out of `rust/kernel/types.rs`

[y86-dev]

rust/kernel/types.rs is a rather non-descriptive, general file that contains code that might be better suited somewhere else:

• ARef<T> and AlwaysRefCounted should be in rust/kernel/sync/aref.rs.
• FromBytes and AsBytes traits and implementations should be in rust/kernel/transmute.rs.

Please create two separate patches for the above. Also take care to fix any imports and rustdoc examples.

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This requires submitting a proper patch to the LKML and the Rust for Linux mailing list. Please recall to test your changes (including generating the documentation if changed, running the Rust doctests if changed, etc.), to use a proper title for the commit, to sign your commit under the Developer's Certificate of Origin and to add a Suggested-by: tag and a Link: tag to this issue. Please see https://rust-for-linux.com/contributing for details.

Please take this issue only if you are new to the kernel development process and you would like to use it as a test to submit your first patch to the kernel. Please do not take it if you do not plan to make other contributions to the kernel.

[nbdd0121]

I feel like convert doesn't coney the semantics of these traits are only performing byte-level transmutation. Maybe transmute.rs?

[plinkr]

Hey! I would like to give this issue a try if no one is working on it

[plinkr]

I sent the patches: https://lore.kernel.org/rust-for-linux/20240918225115.2309224-1-aliet.exposito@gmail.com/T/#t
Thank you very much for the opportunity to work on a good first issue

[sergiocollado]

The patch looks good .... but transmute.rs for me it feels a bit too eldritch and arcane .... convert or convertBytes or something similar sounded better, at least for me. Otherwise looks great!

[ojeda]

@sergiocollado I assume it is following std::mem::transmute.

Applied to rust-next -- thanks everyone!