[llvm] [AArch64][SVE] Fold nested boolean UMIN trees (PR #209234)

[Paul Walker via llvm-commits]

https://github.com/paulwalker-arm approved this pull request.

Looks good to me.  Not sure if you see this in real code but logical_umin_with_umin_2 shows a possible extension whereby nested clamp operations can be simplified to a single clamp of the smallest value.

https://github.com/llvm/llvm-project/pull/209234