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

[David Green via llvm-commits]

https://github.com/davemgreen commented:

It might be worth doing this as a (late) AArch64ISelLowering DAG combine so that the add gets shared between multiple load/store instructions.

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