[llvm] [VPlan] Process simplifyRecipes via a worklist (PR #133977)

[Florian Hahn via llvm-commits]

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@@ -923,7 +923,7 @@ static void recursivelyDeleteDeadRecipes(VPValue *V) {
 }
 
 /// Try to simplify recipe \p R.
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fhahn wrote:

```suggestion
/// Try to simplify recipe \p R and return the simplified VPValue or nullptr if it could not be simplified..
```

https://github.com/llvm/llvm-project/pull/133977