Update arraypartition_gpu.jl

Author: ChrisRackauckas

test/gpu/arraypartition_gpu.jl

@@ -17,3 +17,7 @@ RecursiveArrayTools.recursivefill!(pA, true)
 # Test that regular filling is done using GPU kernels and not scalar indexing
 fill!(pA, false)
 @test all(pA .== false)
+
+a = ArrayPartition(([1.0f0] |> cu, [2.0f0] |> cu, [3.0f0] |> cu))
+b = ArrayPartition(([0.0f0] |> cu, [0.0f0] |> cu, [0.0f0] |> cu))
+@. a + b