[llvm] [VPlan] Dispatch to multiple exit blocks via middle blocks. (PR #112138)

[via llvm-commits]

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@@ -124,6 +124,17 @@ struct VPlanTransforms {
   /// Remove dead recipes from \p Plan.
   static void removeDeadRecipes(VPlan &Plan);
 
+  /// Update \p Plan to account for uncountable exit blocks in \p
+  /// UncountableExitingBlocks by
+  ///  * updating the condition to exit the vector loop to include the early
+  ///    exit conditions
+  ///  * splitting the original middle block to branch to the early exit blocks
+  ///    if taken. Returns false if the transformation wasn't successful.
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ayalz wrote:

```suggestion
  ///    if taken.
```
(returns void)

https://github.com/llvm/llvm-project/pull/112138