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

[Matt Arsenault via llvm-commits]

arsenm wrote:

### Merge activity

* **Nov 8, 9:59 PM EST**: A user started a stack merge that includes this pull request via [Graphite](https://app.graphite.dev/github/pr/llvm/llvm-project/115060).


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