[Vectorize] Use DenseMap::insert_range (NFC) (#133656)

Author: kazutakahirata

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -5415,7 +5415,7 @@ void LoopVectorizationCostModel::collectInstsToScalarize(ElementCount VF) {
         if (!isScalarAfterVectorization(&I, VF) && !VF.isScalable() &&
             !useEmulatedMaskMemRefHack(&I, VF) &&
             computePredInstDiscount(&I, ScalarCosts, VF) >= 0) {
-          ScalarCostsVF.insert(ScalarCosts.begin(), ScalarCosts.end());
+          ScalarCostsVF.insert_range(ScalarCosts);
           // Check if we decided to scalarize a call. If so, update the widening
           // decision of the call to CM_Scalarize with the computed scalar cost.
           for (const auto &[I, Cost] : ScalarCosts) {