[llvm] [LV] Create block in mask up-front if needed. (PR #76635)

[via llvm-commits]

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@@ -138,8 +138,11 @@ class VPRecipeBuilder {
 
   /// A helper function that computes the predicate of the block BB, assuming
   /// that the header block of the loop is set to True or the loop mask when
-  /// tail folding. It returns the *entry* mask for the block BB.
-  VPValue *createBlockInMask(BasicBlock *BB, VPlan &Plan);
+  /// tail folding.
+  void createBlockInMask(BasicBlock *BB, VPlan &Plan);
+
+  // Returns the *entry* mask for the block BB.
+  VPValue *getBlockInMask(BasicBlock *BB);
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ayalz wrote:

```suggestion
  VPValue *getBlockInMask(BasicBlock *BB) const;
```
?

https://github.com/llvm/llvm-project/pull/76635