rust: transmute: Add methods for FromBytes trait

The two methods added take a slice of bytes and return those bytes in
a specific type. These methods are useful when we need to transform
the stream of bytes into specific type.

Since the `is_aligned` method for pointer types has been stabilized in
`1.79` version and is being used in this patch, I'm enabling the
feature. In this case, using this method is useful to check the
alignment and avoid a giant boilerplate, such as `(foo.as_ptr() as
usize) % core::mem::align_of::<T>() == 0`.

Also add `#[allow(clippy::incompatible_msrv)]` where needed until the
MSRV is updated to `1.79`.

Suggested-by: Benno Lossin <benno.lossin@proton.me>
Link: https://github.com/Rust-for-Linux/linux/issues/1119


Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Christian S. Lima <christiansantoslima21@gmail.com>
Link: https://lore.kernel.org/r/20250824213134.27079-1-christiansantoslima21@gmail.com


Acked-by: Miguel Ojeda <ojeda@kernel.org>
[acourbot@nvidia.com: minor rewording of commit messages and doccomments]
[acourbot@nvidia.com: revert slice implementation removal]
[acourbot@nvidia.com: move incompatible_msrv clippy allow closer to site of need]
[acourbot@nvidia.com: call the doctest method]
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>