[AVR] Migrate to new StructType::get owing to Supress all uses of LLVM_END_WITH_NULL

[xiangzhai]

Summary

Hi LLVM developers,

After https://reviews.llvm.org/D32541

static Constant *get(StructType *T, ...) LLVM_END_WITH_NULL;

has been changed to

template <typename... Csts>
  static typename std::enable_if<are_base_of<Constant, Csts...>::value,
                                 Constant *>::type
  get(StructType *T, Csts *... Vs) {
    SmallVector<Constant *, 8> Values{{Vs...}};
    return get(T, Values);
  }

so it doesn't need to end with nullptr any more, then I simply removed nullptr to fix the build issue for AVR backend, please review my patch, thanks a lot!

Regards,
Leslie Zhai

[serge-sans-paille]

LGTM.

lib/Target/AVR/AVRISelLowering.cpp

for (SDValue const &Value : Op->op_values()) {
     Entry.IsSExt = IsSigned;
     Entry.IsZExt = !IsSigned;
     Args.push_back(Entry);
   }
 
   SDValue Callee = DAG.getExternalSymbol(getLibcallName(LC),
                                          getPointerTy(DAG.getDataLayout()));
 
-  Type *RetTy = (Type *)StructType::get(Ty, Ty, nullptr);
+  Type *RetTy = (Type *)StructType::get(Ty, Ty);
 
   SDLoc dl(Op);
   TargetLowering::CallLoweringInfo CLI(DAG);
   CLI.setDebugLoc(dl)
       .setChain(InChain)
       .setLibCallee(getLibcallCallingConv(LC), RetTy, Callee, std::move(Args))
       .setInRegister()
       .setSExtResult(IsSigned)