[NFC][Transforms][Utils] remove useless variable in CloneBasicBlock

Author: dongAxis

llvm/lib/Transforms/Utils/CloneFunction.cpp

@@ -44,7 +44,6 @@ BasicBlock *llvm::CloneBasicBlock(const BasicBlock *BB, ValueToValueMapTy &VMap,
                                   const Twine &NameSuffix, Function *F,
                                   ClonedCodeInfo *CodeInfo,
                                   DebugInfoFinder *DIFinder) {
-  DenseMap<const MDNode *, MDNode *> Cache;
   BasicBlock *NewBB = BasicBlock::Create(BB->getContext(), "", F);
   if (BB->hasName())
     NewBB->setName(BB->getName() + NameSuffix);