[llvm] Revert "[LowerMemIntrinsics] Use correct alignment in residual loop for variable llvm.memcpy" (PR #98295)

[Fabian Ritter via llvm-commits]

ritter-x2a wrote:

It's this one: https://lab.llvm.org/buildbot/#/builders/123/builds/1498
The other listed candidate seems AArch64-specific; and I haven't seen this failure in any recent previous commits.

https://github.com/llvm/llvm-project/pull/98295