[llvm] [llvm][Support] Improvements to ListeningSocket functionality and documentation (PR #84710)

[Michael Spencer via llvm-commits]

Bigcheese wrote:

I think that's fine. In general for timeout tests I would just check that the duration is >= the timeout, and rely on manual testing to make sure it's not too much longer. It's not trivial to figure out a reasonable maximum time for a timeout to take in these kinds of cases, and here knowing that the OS says it timed out is mostly what we care about.

https://github.com/llvm/llvm-project/pull/84710