This patch implements the Denoise node for the realtime compositor. The
denoiser executes on the CPU and we pay for the CPU<->GPU round trip to
memory, so this is not realtime, as one might expected. And is just a
temporary implementation until OIDN supports GPU execution.
This is different from the CPU implementation in that it doesn't use the
auxiliary passes if they were not provided, because using an inflated
buffer of an undefined value doesn't make much sense.
Pull Request: https://projects.blender.org/blender/blender/pulls/107375
e8c660b855