[llvm] [SLP][NFC] Unify code for cost estimation/codegen for buildvector, NFC. (PR #73182)

[Simon Pilgrim via llvm-commits]

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@@ -10341,7 +10470,7 @@ class BoUpSLP::ShuffleInstructionBuilder final : public BaseShuffleAnalysis {
       InVectors.push_back(V1);
   }
   /// Adds another one input vector and the mask for the shuffling.
-  void add(Value *V1, ArrayRef<int> Mask) {
+  void add(Value *V1, ArrayRef<int> Mask, bool = false) {
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RKSimon wrote:

What is the point of this bool argument?

https://github.com/llvm/llvm-project/pull/73182