This commit contains all the changes required for most optimal maximum threads number bump. This is needed to avoid possibly unneeded initialization or data allocation on systems with lower threads count. TODO: Still need to review arrays in render data structures from render_types.h, P.S. We might remove actual bump of max threads from this patch, so when we'll be applying the patch we can do all the preparation work and then do actual bump of max threads. Reviewers: mont29, campbellbarton Reviewed By: mont29, campbellbarton Maniphest Tasks: T43306 Differential Revision: https://developer.blender.org/D1343