[llvm] [GlobalOpt] Fix global SRA incorrect alignment on some elements (PR #115328)

[Bruno De Fraine via llvm-commits]

brunodf-snps wrote:

> LGTM

Thanks. I still added a reduced test case with the example from the bug report. I suppose this should be pre-committed? In that case, you can commit 0a59028 first, and I'll rebase to remove it from this pull request.

(Unless you think the effect is sufficiently clear from the other test cases and a dedicated test case is overkill; then I'll remove it again.)

https://github.com/llvm/llvm-project/pull/115328