Fix gtk reactor test failures on Windows caused by WSAEventSelect's FD_CLOSE behavior
|Reported by:||exarkun||Owned by:|
We discovered a shortcoming in win32eventreactor related to its failure to account for FD_CLOSE only ever being delivered once per socket and fixed it there (#5233). It may be that some of the gtk reactor tests which fail (and are mostly set to skip) on Windows behave as they do for the same reason. We should investigate how gtk exposes close notification to us and whether gtk reactor needs to do something similar to win32eventreactor to keep track of closed, readable connections.