message: Fixed GEP with nullptr type after switch to LLVM 13
diff: @@ -5793,9 +5793,10 @@ MemoryCoalescing::BasePtrInfo MemoryCoalescing::analyseVarOffsetGEP(llvm::GetEle
  std::vector<llvm::Value *> PartialIdxs;
  for (unsigned i = 1; i < FirstConstIdx; ++i)
  PartialIdxs.push_back(GEP->getOperand(i));
  + llvm::Value *tPtr = GEP->getPointerOperand();
  + llvm::Type *tType = llvm::cast<llvm::PointerType>(tPtr->getType()->getScalarType())->getElementType();
  auto ret = ComplexGEPsInfoCache.insert(
  - {GEPVarOffsetData,
  - llvm::GetElementPtrInst::Create(nullptr, GEP->getPointerOperand(), PartialIdxs, "partial_gep")});
  + {GEPVarOffsetData, llvm::GetElementPtrInst::Create(tType, tPtr, PartialIdxs, "partial_gep")});
  DanglingGEP_it = ret.first;
  }
  llvm::Value *DanglingGEP = DanglingGEP_it->second;
  @@ -5808,8 +5809,9 @@ MemoryCoalescing::BasePtrInfo MemoryCoalescing::analyseVarOffsetGEP(llvm::GetEle
  // Get partial GEP type
  llvm::PointerType *PartialType = llvm::cast<llvm::PointerType>(DanglingGEP->getType());
  // Create temporary GEP that will help us to get some useful info
  - llvm::GetElementPtrInst *GEPHelper =
  - llvm::GetElementPtrInst::Create(nullptr, llvm::ConstantPointerNull::get(PartialType), Idxs);
  + llvm::Value *tPtr = llvm::ConstantPointerNull::get(PartialType);
  + llvm::Type *tType = llvm::cast<llvm::PointerType>(tPtr->getType()->getScalarType())->getElementType();
  + llvm::GetElementPtrInst *GEPHelper = llvm::GetElementPtrInst::Create(tType, tPtr, Idxs);
  // Accumulate offset from helper
  llvm::APInt acc(g->target->is32Bit() ? 32 : 64, 0, true);
  bool checker = GEPHelper->accumulateConstantOffset(GEP->getModule()->getDataLayout(), acc);
  