Well ... once again, I find myself in need of another feature. This time, dynamic parallelism.

Looks like this is also part of the C++ runtime API, similar to cooperative groups, for which I already have a PR.

I'm considering using a similar strategy for implementing this feature. I would love to just pin down the PTX, but that has proven to be a bit unclear; however, I will definitely start my search in the PTX ISA and see if there are any quick wins. If not, then probably a similar approach as was taken with the cooperative groups API.

Thoughts?