because the plain wasip1 dosen't have connect/listen,
sometimes embedders play a trick to pass an already connected/listening socket.

eg. https://github.com/yamt/garbage/tree/master/wasm/httpd

unfortunately these tricks don't work well for the current wamr if the embedder uses fd 0-2 for it
(as the above example does by default)
because it has unnecessarily strong assumptions about how fd 0-2 are used.