[clang] [lldb] [llvm] [HLSL] Add Packed Types for pack_ and unpack_ intrinsics (PR #224277)

[Alexander Johnston via llvm-commits]

Alexander-Johnston wrote:

@kmpeng I've cleared out all the pack_ intrinsic code I believe, and done some updates to the type specific code. I think this should be good for review now

https://github.com/llvm/llvm-project/pull/224277