Blender Git Loki

Cycles: delay CUDA and OpenCL initialization to avoid driver crashes.

We've had many reported crashes on Windows where we suspect there is a
corrupted OpenCL driver. The purpose here is to keep Blender generally
usable in such cases.

Now it always shows None / CUDA / OpenCL in the preferences, and only when
selecting one will it reveal if there are any GPUs available. This should
avoid crashes when opening the preferences or on startup.

Differential Revision: https://developer.blender.org/D4265