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

[Bruno De Fraine via llvm-commits]

brunodf-snps wrote:

I think the bug existed since commit 4796b4ae7bccc7b75a26b666fbd554c49b274404.

The updated expected alignments in Transforms/GlobalOpt/globalsra-align.ll revert the changes from that commit, with the exception of `@a.6` (previously `@a.2.2`) which before that commit had alignment 8, and since alignment 16. This is retained, but seems correct to me. 

The tests DebugInfo/X86/global-sra-struct-fit-segment.ll and DebugInfo/X86/global-sra-struct-part-overlap-segment.ll are newer than the aforementioned commit.

CC @nikic 

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