Use Thrust's sort for inputs larger than 2048
Use Thrust's sort for inputs larger than 2048

The blockwide sort kernel only supports inputs up to 2048 elements.
Before this change, attempting to sort inputs with size (2048,4096]
would fail.

Zhen-hao/cutorch,adamlerer/cutorch,wickedfoo/cutorch,LinusU/cutorch,Moodstocks/cutorch,clementfarabet/cutorch,hughperkins/cutorch,clementfarabet/cutorch,LinusU/cutorch,Zhen-hao/cutorch,hughperkins/cutorch,adamlerer/cutorch,Moodstocks/cutorch,torch/cutorch,luketwitter/cutorch,torch/cutorch,Schakirov/cutorch_my,0wu/cutorch,luketwitter/cutorch,yvan-sraka/cutorch,0wu/cutorch,torch/cutorch,wickedfoo/cutorch,Schakirov/cutorch_my,yvan-sraka/cutorch