Redesigns the TBB and Serial backends and the vtkm::exec::Task concept so that
we can re-use the same launching logic for all Worklets, instead of generating
per worlet code. To keep the performance the same the TilingTask now is past
a range of indices to work on, rather than a single index.
Binary size reduction:
WorkletTests_SERIAL old - 19MB
WorkletTests_SERIAL new - 18MB
WorkletTests_TBB old - 39MB
WorkletTests_TBB new - 18MB
libvtkAcceleratorsVTKm old - 48MB
libvtkAcceleratorsVTKm new - 19MB
Previously WorkletInvokeFunctor inherited from vtkm::exec::FunctorBase,
which is also the base class for all users Worklets and for all functors
based to DeviceAdapter::Schedule.
This is done for a few reasons. The first is that we reduce the
minimum size of user worklets. Previously the users worklet would hold
a reference to the error message, and so would the wrapper class added
when calling DeviceAdapter::Schedule. Now we only have the users worklet
holding a reference.
Second, by refactoring to have two base classes we can better improve
the documentation on what responsibilities FunctorBase.h has, compared
to TaskBase.
