[llvm] [libc++] Add Docker images to support incoming pre-merge CI transition (PR #144597)

[Aiden Grossman via llvm-commits]

boomanaiden154 wrote:

> Ah, interesting, I wasn't aware of that file. Do you think there is any way that we'd store these inside the monorepo? 

We theoretically can, but it makes versioning, deploying updates, and testing quite a bit more annoying because you now need to update the monorepo and then look at stuff on the terraform side. We originally wanted to keep the premerge infrastructure definitions in the monorepo, but @joker-eph suggested putting it in llvm-zorg because it is infrastructure and we did not really have any use cases at the time for needing to keep things in the monorepo.

Either way, it will be easier for us if we can keep everything in the same place. I'd be open to moving over the existing IaaC in llvm-zorg to the monorepo if there is enough interest and no significant objections though.

> It's a huge simplification for contributors when everything is accessible from the monorepo -- historically this has been a pain point when we were still using buildbot and some of our configuration lived in llvm-zorg.

Yeah, agreed. The inconsistency can make things a bit more annoying.

https://github.com/llvm/llvm-project/pull/144597