[llvm] [CMake] Make precompiled headers opt-in for ccache builds (PR #141927)

[Kajetan Puchalski via llvm-commits]

mrkajetanp wrote:

> It's different from Github in that it's persistent across builds inside the same container. It could even be a single runner that's messed up somewhere.

Oh I see, that sounds like it could indeed be the cause of this.

> Can we hold off on landing this until after we sunset Buildkite (should happen in the next couple days)? If it's still occurring on the Github side we can land it, but otherwise we probably don't need it.

Sure, I'm happy to wait. Is there somewhere I can track the progress of moving the CI to GitHub?

https://github.com/llvm/llvm-project/pull/141927