`XArray` is an efficient sparse array of pointers. Add a Rust
abstraction for this type.
This implementation bounds the element type on `ForeignOwnable` and
requires explicit locking for all operations. Future work may leverage
RCU to enable lockless operation.
Inspired-by: Maíra Canal <[email protected]>
Inspired-by: Asahi Lina <[email protected]>
Reviewed-by: Andreas Hindborg <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Signed-off-by: Tamir Duberstein <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Andreas Hindborg <[email protected]>
