The callables generated by OSL reference other external functions
(defined in the OSL services module), in which case OptiX cannot
calculate the right stack size just based on the callable alone, it needs to
know all functions linked together in the pipeline to get to an accurate
result. `optixProgramGroupGetStackSize` has an optional pipeline
argument for this purpose, so make use of that to ensure the correct
stack size is calculated.
Ref #122779
Pull Request: https://projects.blender.org/blender/blender/pulls/123368
56c1163c21