[$] Introducing io_uring_spawn

The traditional mechanism for launching a program in a new process on Unixsystems-forking and execing-has been with us for decades, but it is notreally the most efficient of operations. Various alternatives have beentried along the way but have not supplanted the traditional approach. A newmechanism created by Josh Triplett adds process creationto the io_uring asynchronous I/O API andshows great promise; he came to the 2022Linux Plumbers Conference (LPC) to introduce io_uring_spawn.