Test merge_by_key with thrust::seq in __device__ code.
Test merge_by_key with thrust::seq in __device__ code.

xiongzhanblake/thrust,dachziegel/thrust,thrust/thrust,jaredhoberock/thrust,arnabgho/thrust,zhenglaizhang/thrust,zeryx/thrust,jaredhoberock/thrust,sarvex/thrust,sarvex/thrust,thrust/thrust,marksantos/thrust,thvasilo/thrust,thvasilo/thrust,xiongzhanblake/thrust,arnabgho/thrust,mohamed-ali/thrust,raygit/thrust,Ricardo666666/thrust,Ricardo666666/thrust,mohamed-ali/thrust,GrimDerp/thrust,jaredhoberock/thrust,egaburov/thrust,dachziegel/thrust,GrimDerp/thrust,Ricardo666666/thrust,sdalton1/thrust,thvasilo/thrust,xiongzhanblake/thrust,zeryx/thrust,sdalton1/thrust,zhenglaizhang/thrust,marksantos/thrust,mohamed-ali/thrust,andrewcorrigan/thrust-multi-permutation-iterator,raygit/thrust,thrust/thrust,dachziegel/thrust,arnabgho/thrust,xiongzhanblake/thrust_src,marksantos/thrust,zhenglaizhang/thrust,andrewcorrigan/thrust-multi-permutation-iterator,egaburov/thrust,thrust/thrust,zeryx/thrust,jaredhoberock/thrust,xiongzhanblake/thrust_src,egaburov/thrust,andrewcorrigan/thrust-multi-permutation-iterator,xiongzhanblake/thrust_src,sdalton1/thrust,sarvex/thrust,raygit/thrust,thrust/thrust,GrimDerp/thrust,jaredhoberock/thrust