[llvm] [LV] Simplify live-out extraction for first-order recurrence phis when tail folding (PR #176108)

[Luke Lau via llvm-commits]

https://github.com/lukel97 approved this pull request.

LGTM, this makes sense to me. The penultimate element of the FOR = the penultimate element of the splice, since the splice is just the FOR with a single element prepended to the front.

https://github.com/llvm/llvm-project/pull/176108