OpenBSD port request

[Scorpox59]

Hi gingerBill,
I would like to try Odin on OpenBSD, but it doesn't compile.

clang src/main.cpp -Wno-switch -Wno-pointer-sign -Wno-tautological-constant-out-of-range-compare -Wno-tautological-compare -Wno-macro-redefined -std=c++14 -DGIT_SHA="" -DODIN_VERSION_RAW="dev-2021-05" -g -pthread -ldl -lm -lstdc++ -o odin
In file included from src/main.cpp:3:
In file included from src/common.cpp:19:
src/gb/gb.h:201:4: error: This UNIX operating system is not supported
#error This UNIX operating system is not supported
^
src/gb/gb.h:321:12: fatal error: 'sys/sendfile.h' file not found
#include <sys/sendfile.h>
^~~~~~~~~~~~~~~~

[Platin21]

There was once a pull request for this you might want to take a look at that.
This is it #745

[ghost]

I did some of the FreeBSD port quite a while ago, and I was working on NetBSD but never finished it. I can't remember everything that I did for FreeBSD, but I think you need to add defines, you might have to change the src/gb/gb.h file. You will also need to add targets to src/build_settings.cpp, I think. And then add support to the core library (which required looking up how some things are defined in FreeBSD).

Although, much of this work for FreeBSD was done prior to the new backend, so I'm not sure what has changed - I'm not even sure if FreeBSD works anymore since the switch :D
But you can see what I did for FreeBSD Here: #734