a7697c8655
These intrinsics currently assume natural alignment. Instead, respect the alignment attribute on the intrinsic. Teach InstCombine to improve that alignment. If desired I could also adjust the clang frontend to add alignment annotations equivalent to the previous behavior, but I don't see any indication that such an assumption is correct in the ARM intrinsics docs. Fixes https://github.com/llvm/llvm-project/issues/59081.