Note: This is not for review.
As follow up on D98349 and D98678, this patch shows that we can
eliminate the members of TaskDescr by introducing a run-sched-var in the
ICVStateTy. Other functionality is already covered by the ICVStateTy.
The task.cu uses need to be converted to the new system, e.g., by
calling enterDataEnvironment instead of the task copy stuff. Other
than that, this looks like we only need to remove all the old plumbing.
Unclear how to merge/split D98349 and this one and the cleanup follow