Fix shfl_down warnings with cuda 9
Fix shfl_down warnings with cuda 9

9prady9/arrayfire,arrayfire/arrayfire,umar456/arrayfire,arrayfire/arrayfire,arrayfire/arrayfire,arrayfire/arrayfire,umar456/arrayfire,umar456/arrayfire,9prady9/arrayfire,9prady9/arrayfire,umar456/arrayfire,9prady9/arrayfire