[llvm] AMDGPU: Default to selecting frame indexes to SGPRs (PR #115060)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> Hi @arsenm, can you take a look at the following case. It still fails with [#115747](https://github.com/llvm/llvm-project/pull/115747). Thanks.

This one is #115977


https://github.com/llvm/llvm-project/pull/115060