[Bf-cycles] Updated standalone repository

[Stefan Werner]

Hi,

as announced in the Blender Rendering Meeting, I have updated the Cycles repository to reflect Blender 2.92. An additional branch was created that will be kept in sync with Blender 2.83 LTS. I have also added tags that mark the sync points for the last few Blender releases (blender-v2.83.12, blender-v2.90.1, blender-v2.91.2, blender-v2.92.0). I did not tag a new Cycles version.

Please report any issues (and if you can, provide a patch) that you encounter as a result of this merge. I have not tested all possible permutations of build platforms and options.

-Stefan