[llvm] [Coro] Amortize debug info processing cost in CoroSplit (PR #109032)

[Artem Pianykh via llvm-commits]

artempyanykh wrote:

@adrian-prantl, @felipepiovezan have you had a chance to take a closer look? Could you advise on what would be the best way to proceed with reviewing this PR?

https://github.com/llvm/llvm-project/pull/109032