See: https://illumos.org/man/5/epoll

Idea: move logic from src/unix/linux-core.c to src/unix/epoll.c and share that between Linux and Illumos.

Motivation:

• removes 250-300 lines of code from src/unix/sunos.c
• switches to much more battle-hardened code
• makes libuv more efficient because it no longer has to accommodate this event ports quirk:

diff --git a/src/unix/core.c b/s

What should happen if deliver_cancel raises an exception? In the current implementation, the shielded cancel scope will prevent it from propagating until the process exits, which might take a while if the crash occurred before signaling the process in any way. Maybe on exception from a user-specified deliver_cancel we should call the default deliver_cancel to kill the process? Or just kill() since