[llvm] [AArch64] Allow only LSL to be folded into addressing mode (PR #69235)

[David Green via llvm-commits]

https://github.com/davemgreen approved this pull request.

It might be a good idea to add this as a mir test, as GISel could change in the future to be more like SDAG.

Otherwise LGTM

https://github.com/llvm/llvm-project/pull/69235