Tier System: `x86_64-openbsd`

[andrewrk]

Here's the issue to track OpenBSD support. The current goal is Tier 3, since Zig can't even build on OpenBSD yet. Once Zig reaches Tier 3 this issue will get renamed to Tier 2, and so on. @Aversiste has started the effort in #1921.

[andrewrk]

Here is some partially finished code that one can use for inspiration: #1921

[andrewrk]

SourceHut has OpenBSD images now: https://man.sr.ht/builds.sr.ht/compatibility.md#openbsd

[voutilad]

FWIW, OpenBSD recently imported LLVM 8.0.0 into base: https://marc.info/?l=openbsd-cvs&m=156132754603489&w=2

It's available now in the latest -current snapshots for anyone interested in this issue.

Edit: SourceHut seems to have the latest release, but doesn't support -current snapshots, so anyone working on OpenBSD compatibility can't readily solve the CI needs until the next OpenBSD release later this year.