UB in AtomicBuffer

[dtolnay]

A lot more of the atomic_buffer.rs API needs to be audited than what was done in closing my previous issue #16.

For example:

use aeron_rs::concurrent::atomic_buffer::AtomicBuffer;

fn main() {
    AtomicBuffer::wrap_raw_slice(&mut [] as *mut [u8; 0] as *mut [u8; 1024])
        .get_bytes(16, &mut "");
}

Segmentation fault (core dumped)

and:

use aeron_rs::concurrent::atomic_buffer::AtomicBuffer;

fn main() {
    println!("{}", AtomicBuffer::wrap_slice(&mut [1; 16]).get::<&str>(0));
}

Segmentation fault (core dumped)

and:

use aeron_rs::concurrent::atomic_buffer::AtomicBuffer;

fn main() {
    let buf = AtomicBuffer::wrap_slice(&mut [0; 16]);
    let s = buf.as_ref::<&str>(0);
    buf.set_memory(0, 16, 1);
    println!("{}", s);
}

Segmentation fault (core dumped)

From a brief skim, there are a lot more problems than just these.