ZFlecs: no libc

[Olle-Lukowski]

I was wondering if it would be possible to eventually remove the dependency on libc from zflecs? I'm trying to keep my codebase as 'ziggy' as possible, and would really appreciate this.

[hazeycode]

flecs depends on a number of C standard libary APIs. It would technically be possible to roll our own implementation of these and drop the libc requirement but given that there is a libc available for our target platforms, it's unlikely this would ever be prioritised over other things.