mksysinfo: Make sure EPOLL_CLOEXEC is defined.
mksysinfo: Make sure EPOLL_CLOEXEC is defined.

R=iant
CC=gofrontend-dev
https://golang.org/cl/5545055

anlhord/gofrontend,qskycolor/gofrontend,qskycolor/gofrontend,qskycolor/gofrontend,golang/gofrontend,golang/gofrontend,golang/gofrontend,qskycolor/gofrontend,golang/gofrontend,qskycolor/gofrontend,anlhord/gofrontend,anlhord/gofrontend,anlhord/gofrontend,anlhord/gofrontend,anlhord/gofrontend,qskycolor/gofrontend,anlhord/gofrontend,qskycolor/gofrontend