[clang] [llvm] [HLSL][DXIL][SPRIV] Added `GroupMemoryBarrier()` (PR #185383)

[Sietze Riemersma via cfe-commits]

KungFuDonkey wrote:

I am back from a small vacation and I noticed this didn't get merged yet. I think it was misinterpreted that I would add the assertion now for Device memory.

Anyway I will add them now and update to latest main. Is there anything else that needs to be done before this PR can go in?

https://github.com/llvm/llvm-project/pull/185383