[llvm] [Xtensa] Implement vararg support. (PR #117126)

[Matt Arsenault via llvm-commits]

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@@ -304,13 +318,14 @@ SDValue XtensaTargetLowering::LowerFormalArguments(
     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) const {
   MachineFunction &MF = DAG.getMachineFunction();
   MachineFrameInfo &MFI = MF.getFrameInfo();
+  XtensaMachineFunctionInfo *XtensaFI = MF.getInfo<XtensaMachineFunctionInfo>();
+  EVT PtrVT = getPointerTy(MF.getDataLayout());
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arsenm wrote:

In context this probably should be getFrameIndexTy 

https://github.com/llvm/llvm-project/pull/117126