[StructurizeCFG] Remove one SSAUpdater::AddAvailableValue. NFCI. (#115472)

Author: jayfoad

llvm/lib/Transforms/Scalar/StructurizeCFG.cpp

@@ -619,7 +619,6 @@ void StructurizeCFG::insertConditions(bool Loops) {
     BasicBlock *SuccFalse = Term->getSuccessor(1);
 
     PhiInserter.Initialize(Boolean, "");
-    PhiInserter.AddAvailableValue(&Func->getEntryBlock(), Default);
     PhiInserter.AddAvailableValue(Loops ? SuccFalse : Parent, Default);
 
     BBPredicates &Preds = Loops ? LoopPreds[SuccFalse] : Predicates[SuccTrue];