[llvm] [LV] Reuse VPReplicateRecipe to handle scalar stores in exit block. (PR #106342)

[Mel Chen via llvm-commits]

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@@ -8956,8 +8965,17 @@ LoopVectorizationPlanner::tryToBuildVPlanWithVPRecipes(VFRange &Range) {
       // with the final reduction value will be added to the exit block
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Mel-Chen wrote:

76d4dde1b0a9a7a6c0184180ad02f77db23c7447
And replace `last` with `final` for aligning the term with the comment of `isInvariantStoreOfReduction`.
```
  /// Returns True if given store is a final invariant store of one of the
  /// reductions found in the loop.
  bool isInvariantStoreOfReduction(StoreInst *SI);
```

https://github.com/llvm/llvm-project/pull/106342