async_copy! fixes (#69)

* Add async copies to the test suite

Author: lcw

src/backends/cpu.jl

@@ -28,8 +28,6 @@ function wait(cpu::CPU, ev::MultiEvent, progress=nothing)
 end
 
 function wait(::CPU, ev::CPUEvent, progress=nothing)
-    ev.task === nothing && return
-    
     if progress === nothing
         wait(ev.task)
     else

test/async_copy.jl

@@ -22,4 +22,4 @@ M = 1024
 if has_cuda_gpu()
     copy_test(CUDA(), CuArray, M)
 end
-copy_test(CPU(), CuArray, M)
+copy_test(CPU(), Array, M)

test/runtests.jl

@@ -21,6 +21,10 @@ end
     include("nditeration.jl")
 end
 
+@testset "async_copy!" begin
+    include("async_copy.jl")
+end
+
 @testset "Events" begin
     include("events.jl")
 end