[llvm] [RISCV] Cost ordered bf16/f16 w/ zvfhmin reductions as invalid (PR #114250)

[Harald van Dijk via llvm-commits]

hvdijk wrote:

Thanks! Happy to confirm that where I originally saw the assertion failure is fixed by that, and is doing the right thing. Could that fix also be pushed to 20.x? (Also happy to take on that cherry-pick if you prefer.)

https://github.com/llvm/llvm-project/pull/114250