brson/libuv — pull request #2 by jld (2013-08-25 02:56:56+00:00)
Title: unix/udp: Avoid SO_REUSEPORT on Linux even if headers define it.

Newer Linux kernels have it, so their headers have it, but if the running
kernel is older it will fail, and SO_REUSEADDR still implies it.

There's a better fix for this in 17452cd0e, but it doesn't apply cleanly
to the older version currently used by Rust.