[llvm] [VPlan] Support multiple F(Max|Min)Num reductions. (PR #161735)

[via llvm-commits]

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@@ -879,52 +873,71 @@ bool VPlanTransforms::handleMaxMinNumReductions(VPlan &Plan) {
   }
 
   VPBasicBlock *LatchVPBB = LoopRegion->getExitingBasicBlock();
-  VPBuilder Builder(LatchVPBB->getTerminator());
-  auto *LatchExitingBranch = cast<VPInstruction>(LatchVPBB->getTerminator());
-  assert(LatchExitingBranch->getOpcode() == VPInstruction::BranchOnCount &&
+  VPBuilder LatchBuilder(LatchVPBB->getTerminator());
+  VPValue *IsNaNLane = nullptr;
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ayalz wrote:

```suggestion
  VPValue *AllNaNLanes = nullptr;
```
?

https://github.com/llvm/llvm-project/pull/161735