[clang] [llvm] [CIR][CUDA][NFC] Add skeleton for NVPTX target lowering (PR #182645)

[Ayokunle Amodu via cfe-commits]

ayokunle321 wrote:

This patch is quite big, but that's because there is a lot of code dependencies. If It needs to be split, I'd be happy to do so.

https://github.com/llvm/llvm-project/pull/182645