[llvm] [SPARC] Preserve liveins after leaf register remapping (PR #213359)

[Kirill A. Korinsky via llvm-commits]

catap wrote:

So, here rebased version which can go first, and I'll prepare new cee7b71929312666c5cf48eb79873893811b99a7 after it is merged.

I think this way is cleaner.

https://github.com/llvm/llvm-project/pull/213359