runtime: utilize EVFILT_USER to wake up kevent for kqueue
Fixes #66760
Change-Id: I6ba5bc5b00506b66cb8dc3984a61f32a6358d9bc
Reviewed-on: https://go-review.googlesource.com/c/go/+/577895
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Run-TryBot: Andy Pan <panjf2000@gmail.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>