The libnode packs' smoke program (#1684) still used the pump/alive/
backend_fd entries that the hosted loop (#1696) replaced, so every
Build libnode pack job failed to compile it. It now provides the full
host table and dispatcher and runs Node's event loop once after starting
the asynchronous calls, as the runtime does at the end of a program.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>