[llvm] Reapply "[LV] Enable scalable FindLast on RISCV. (#184931)" (PR #190938)

[Craig Topper via llvm-commits]

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@@ -3219,6 +3219,33 @@ void VPlanTransforms::optimizeEVLMasks(VPlan &Plan) {
   }
 }
 
+// Fixup FindIV reductions. In RISCV, the last 2 iterations might not operate
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topperc wrote:

```suggestion
// Fixup FindIV reductions. In RISC-V, the last 2 iterations might not operate
```

RISC-V is a trademark and should be spelled correctly whenever possible.

https://github.com/llvm/llvm-project/pull/190938