[llvm] [PEI][PowerPC] Fix false alarm of stack size limit (PR #65559)

[Nemanja Ivanovic via llvm-commits]

https://github.com/nemanjai approved this pull request.

Were we always getting this warning on the tests added in https://github.com/llvm/llvm-project/commit/5018a5dcbe70a9e2e39341762ec0ca0ad76d28b4?
My initial reaction to this was that the test case needs to show an actual access on a large stack frame, but we already have that in `test/CodeGen/PowerPC/huge-frame-size.ll`
Maybe it would be nice to add these cases to the same file since this is very related.

Otherwise, LGTM

https://github.com/llvm/llvm-project/pull/65559