Blender Git Loki

Cycles X: Improve performance of transparent shadows with OptiX

This changes the shadow record-all any-hit program to accept all
hits (return without calling `optixIgnoreIntersection`) beyond
the furthest distance recorded after the maximum number of hits
that can be recorded was reached.
OptiX will not call the any-hit program anymore for hits beyond
the distance of the accepted hits and also reduces the current
ray length behind the scenes. As a result performance improves
drastically in scenes where shadow rays can hit a lot of
transparent objects, like the "koro" benchmark scene.

With this applied I now get similar performance with both CUDA
and OptiX in "koro". Not quite perfect yet, but much better than
before.

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D12524