@CorvidCrone I got an archive.org record of a blog post that links a badly-compressed youtube video of a talk that has a briefly skipped past slide with a sentence about the API you're interested in.

I'm surprised there's no sign "Beware of the Leopard".

(There are bits of LLVM's advanced features that feel like they're documented exactly like this. Maybe they improved it. I doubt it, but maybe...)