Investigate getting / importing an MPSC / MPMC queue for logging

[padenot]

It's easy to get one in rust, but our backends aren't all in rust, and it will be best to have something in the meantime, see mozilla/cubeb-coreaudio-rs#180.

@ChunMinChang suggests https://github.com/facebook/folly/blob/fe37daacf861700585d303b277138cb18a92686c/folly/MPMCQueue.h or https://github.com/cameron314/concurrentqueue.

[behunin]

For your consideration:
https://github.com/yuzu-emu/yuzu/blob/master/src/common/bounded_threadsafe_queue.h

I contributed this queue to that project.

Its base design came from:
https://github.com/rigtorp/MPMCQueue