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

[Jun Wang via cfe-commits]

jwanggit86 wrote:

@krzysz00 Let me make sure I understand the requirements correctly. Based on my understanding, the following are the requirements. Pls let me know if there are any mistakes.

1. Create a new function attribute for the number of workgroups (maybe 2 attributes, one for max, and one for min).
2. The function attribute consists of 3 unsigned integers, one for each of the x, y, and z dimensions.
3. If the numbers are all valid, they are listed in the medata data section of the .s file.
4. What the compiler does with the numbers is left for future work.

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