Add an indirect rendering library
Created by: kbrenneman
Using a fallback vendor for indirect rendering works for now, but a better long-term solution would be to add a dedicated indirect rendering library to libglvnd.
The indirect rendering library should use the same interface as a normal vendor library, but it would be independent of any hardware vendor library. libGLX would load and use the indirect rendering library the same way it uses a fallback vendor library now.
The first reason is that it removes the requirement to have another vendor library installed. In addition, it removes the need to add a symlink to another vendor library, which is the one remaining place where different installers or package managers would have to step on each other.
The second reason is that the indirect rendering library would serve as an example of how a vendor library works and how the ABI works. Developers could use it as a reference when building a hardware vendor library.