Deprecate `VirtualObjectHandle` and all other classes that are used to
implement objects with virtual methods in the execution environment.
Additionally, the code is updated so that if the
`VTKm_NO_DEPRECATED_VIRTUAL` flag is set none of the code is compiled at
all. This opens us up to opportunities that do not work with virtual
methods such as backends that do not support virtual methods and dynamic
libraries for CUDA.
It is questionable whether there is a point to having a token object
when transfering a virtual object to a device (since there is a handle
object that is managing it anyway). Back out of passing the token all
the way down unless there is an actual need for that.
Marked the old versions of PrepareFor* that do not use tokens as
deprecated and moved all of the code to use the new versions that
require a token. This makes the scope of the execution object more
explicit so that it will be kept while in use and can potentially be
reclaimed afterward.
Now that the dispatcher does its own TryExecute, filters do not need to
do that. This change requires all worklets called by filters to be able
to execute without knowing the device a priori.
Also add a throwFailedRuntimeDeviceTransfer that throws a nicely
detailed message on why a something couldn't be transfered to
the requested device adapter.
* Add FindDeviceAdapterTagAndCall
* Add support for multiple arguments to be passed to the functor in
'ForEachValidDevice' and 'FindDeviceAdapterTagAndCall'.
