Update NVIDIA CUB submodule to v1.8.0
Update NVIDIA CUB submodule to v1.8.0

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