Add FreeBSD support, round 1

[fluffykhv]

Port patches from FreeBSD ports tree (https://github.com/freebsd/freebsd-ports/tree/main/security/sssd2/files), round one

[alexey-tikhonov]

Hi @fluffykhv,
thank you for the contribution.

Is "Add FreeBSD support, round 1" a single huge patch in FreeBSD repo?
If this is a set of patches, wouldn't it make sense to have a commit per patch to make the review easier?

[emaste]

Patches in the FreeBSD ports collection are typically per-file rather than per-logical-change, so it may not be straightforward to recreate an incremental patch set. If you look at the URL above you'll see the per-file patches. This is admittedly not ideal from the perspective of collaboration with an upstream.

Looking at the history (e.g. https://github.com/freebsd/freebsd-ports/commits/main/security/sssd2/files) gives some insight, and you can see some logical changes that could be applied individually e.g. freebsd/freebsd-ports@9a40ff8.

If you want a patch set of logical changes we'll have to curate the patches in the ports tree.