Blender Git Loki

CMake: Allow to use pre-compiled CentOS libraries

The goal is to make it able to use pre-compiled CentOS libraries on a
more modern system. Main issue was that it's possible that the compiler
on a newer version is defaulting to different C++11 ABI.

This change makes it so that if there is NO native libraries in the
lib folder and there IS pre-compiled CentOS folder, it will be used and
compiler will be forced to old ABI.

Differential Revision: https://developer.blender.org/D6031