[clang] [llvm] [HLSL][SPRIV] Handle signed RWBuffer correctly (PR #144774)

[Steven Perron via cfe-commits]

s-perron wrote:

@michalpaszkowski The SPIR-V backend meeting was canceled, so we won't be able to talk about this there. Do you have any feedback?

https://github.com/llvm/llvm-project/pull/144774