[llvm] [IVDescriptor] Explicitly check for isMinMaxRecurrenceKind in getReductionOpChain. NFC (PR #132025)

[Mel Chen via llvm-commits]

https://github.com/Mel-Chen approved this pull request.

LGTM, but please address David's comment before merging.

https://github.com/llvm/llvm-project/pull/132025