Revert "Fix HDF5ExternalArray behavior on contiguous arrays"
Revert "Fix HDF5ExternalArray behavior on contiguous arrays"

Somehow this now crashes despite nothing changing with HDF5ExternalArray.

glennhickey/hal,glennhickey/hal,glennhickey/hal,glennhickey/hal,glennhickey/hal,glennhickey/hal,glennhickey/hal,glennhickey/hal