[llvm-branch-commits] [llvm] [19.x] Backport standalone build fixes for offload (PR #118643)

[Michał Górny via llvm-branch-commits]

mgorny wrote:

Thanks! Since it's a nice setup, and pretty much was broken before, I don't think there's a point in a release note.

https://github.com/llvm/llvm-project/pull/118643