[compiler-rt] [llvm] [SPARC] Allow overaligned `alloca`s (PR #107223)

[via llvm-commits]

koachan wrote:

Okay, XFAIL-ed the test on SPARC for now.
If it turns out that the test is irrelevant then I think it's better to do the removal as a separate PR.

https://github.com/llvm/llvm-project/pull/107223