CLOEXEC on old Linux kernel.

[AlexKotik]

Hello. I'm trying to make async sockets work on old embedded system with an old 
Linux kernel (2.4 brunch) and SOCK_CLOEXEC/O_CLOEXEC appeared in 2.6 brunch 
according to manuals. Nativesockets in Nim are using CLOEXEC internally when 
creating a socket. I'd like to use asyncnet for async sockets and not rewriting 
it myself using posix module. Is there any way I could make Nim's builtin async 
sockets work without CLOEXEC? Or rewriting it myself using the posix APIs is 
the only option?