[llvm] [AArch64] merge index address with large offset into base address (PR #72187)

[via llvm-commits]

vfdff wrote:

hi @efriedma-quic @efriedma-quic 
  Because I don't fix out how the check the loop invariant in `AArch64DAGToDAGISel` to avoid some regression cases, so I roll back solution to the 1st method, rebased the patch in [#75343](https://github.com/llvm/llvm-project/pull/75343)

https://github.com/llvm/llvm-project/pull/72187