[clang] [clang] Lower _BitInt(129+) to a different type in LLVM IR (PR #91364)

[Harald van Dijk via cfe-commits]

hvdijk wrote:

Thanks for doing this, it's unfortunate that Clang is in a rather broken state with these types right now and it will be good to see improvement. I think the approach you're taking here is the only approach that will work.

https://github.com/llvm/llvm-project/pull/91364