[llvm] [AMDGPU] Compiler should synthesize private buffer resource descriptor from flat_scratch_init (PR #79586)

[via llvm-commits]

alex-t wrote:

> Thank you for the nit changes! This LGTM, as long as you at least put the FIXME in the docs in the initial commit. I'm happy to update it after-the-fact if it unblocks you

I have updated the llvm/docs/AMDGPUUsage.rst. Could you please see if it seems like what you want?

https://github.com/llvm/llvm-project/pull/79586