[PATCH] Core: detect valid error numbers at run-time

[Piotr Sikora]

Hey Maxim,

> This looks utterly wrong.  You are removing proper support for
> platforms with sys_nerr (including Linux and FreeBSD) and use
> instead the workaround designed to somehow work on other
> platforms.

Use of sys_nerr is deprecated, so it's not a perfect solution,
but fair enough, I'll rework this...

Best regards,
Piotr Sikora