[llvm] [AArch64] Move BSL generation to lowering. (PR #151855)

[Ricardo Jesus via llvm-commits]

https://github.com/rj-jesus commented:

Hi @davemgreen, I think this sounds like a good idea. The free variable cases I looked at recently should be unaffected by this change in any case. :)

https://github.com/llvm/llvm-project/pull/151855