Instead of having a single specialization for sort and zip handles,
we know handle any fancy handles being passed to the cuda device adapter.
This was done by reworking how we represent fancy iterators inside thrust,
and instead of using a transform iterator + counting iterator we just use
a iterator_facade.
This is required so that we can use ArrayHandleZip with Sort/Reduce and
custom comparison operators. ArrayZip and PortalValue don't combine
well together, when used with DeviceAlgorithm that has a custom operator.
The custom operator is actually passed the PortalValue instead of
the real values, and by that point we can't fix anything since we
don't know what the original operator is.
Porting the dax device adapter over to vtkm. Unlike the dax version, doesn't
use the thrust::device_vector, but instead uses thrust::system calls so that
we can support multiple thrust based backends.
Also this has Texture Memory support for input array handles. Some more work
will need to be done to ArrayHandle so that everything works when using an
ArrayHandle inplace with texture memory bindings.
