vlib/net raw.c.v + udp.c.v: isize returned as !int / passed as int — latent type errors surface when net is fully type-checked #3

Mirror of cx-home/cx-private#773 (V-source mirror policy).

vlib/net/raw.c.v:88,:93 and vlib/net/udp.c.v:92,:97 return isize where the fn signatures say !int, and pass isize to socket_error(int). The checker only reaches these when a program's import graph forces full type-checking of net.raw/net.udp (repro: one V file importing both net and the cx platform module). Fix: explicit int conversions or widen the signatures; upstream-bundle candidate.