The source project of this merge request has been removed.
pw: fix build on FreeBSD by using local eventfd definition
The Rust libc crate currently targets FreeBSD 10 (and will soon be updated to target 12), but eventfd has only been added to FreeBSD 13.
Unfortunately the Rust ecosystem still has no solution for targeting particular OS versions, so even after eventfd gets added to the libc crate, that definition won't be usable until the targeted version changes again.
We'll have to use a local 'extern' eventfd definition.