AArch64: Fix hardcoding calling convention of sincos_stret (NFC) (#144336)

Author: arsenm

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

@@ -5061,9 +5061,10 @@ SDValue AArch64TargetLowering::LowerFSINCOS(SDValue Op,
 
   StructType *RetTy = StructType::get(ArgTy, ArgTy);
   TargetLowering::CallLoweringInfo CLI(DAG);
+  CallingConv::ID CC = getLibcallCallingConv(LC);
   CLI.setDebugLoc(dl)
       .setChain(DAG.getEntryNode())
-      .setLibCallee(CallingConv::Fast, RetTy, Callee, std::move(Args));
+      .setLibCallee(CC, RetTy, Callee, std::move(Args));
 
   std::pair<SDValue, SDValue> CallResult = LowerCallTo(CLI);
   return CallResult.first;