Efficient abstraction for memory buffers aligned to 16 bytes (u128) with both owned and shared
variants.
[OwnedAlignedBuffer] represents a memory location aligned to 16 bytes that can be modified.
[SharedAlignedBuffer] can't be modified but supports cheap reference-counting clones (like
Arc, but much more efficient).
Does not require a standard library (no_std) but does require allocator and atomics.