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

[Scott Linder via llvm-commits]

slinder1 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

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