[llvm] [SelectionDAG] Optimize unaligned load stores to realign after offset (PR #145309)

[Acthinks Yang via llvm-commits]

Acthinks wrote:

I haven't found a good way to solve this problem. This optimization scenario is limited. Is it really necessary to do it, or should the user manually rearrange the struct layout?

https://github.com/llvm/llvm-project/pull/145309