[llvm] [clang] [AMDGPU] Adding the amdgpu-num-work-groups function attribute (PR #79035)

[Krzysztof Drewniak via cfe-commits]

krzysz00 wrote:

@arsenm Are you suggesting that these should instead be a range of minimum/maximum number of workitems globally?

https://github.com/llvm/llvm-project/pull/79035