[clang] [CIR][NVPTX] Add support for NVVM half type builtins (PR #221859)

[Ayokunle Amodu via cfe-commits]

ayokunle321 wrote:

Hi @andykaylor should've probably asked you take a look at this as well just to have another eye. Lmk if you have any nit.

https://github.com/llvm/llvm-project/pull/221859