Lower varargs correctly in deopt bundle lowering

Earlier we were ignoring varargs in LowerCallSiteWithDeoptBundle because
populateCallLoweringInfo does not set CallLoweringInfo::IsVarArg.

llvm-svn: 264354
diff --git a/llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
index bf9f1fa..39fea62 100644
--- a/llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
@@ -827,6 +827,7 @@
   unsigned ArgBeginIndex = CS.arg_begin() - CS.getInstruction()->op_begin();
   populateCallLoweringInfo(SI.CLI, CS, ArgBeginIndex, CS.getNumArgOperands(),
                            Callee, CS.getType(), false);
+  SI.CLI.IsVarArg = CS.getFunctionType()->isVarArg();
 
   auto DeoptBundle = *CS.getOperandBundle(LLVMContext::OB_deopt);