Some in-game bad textures disappeared. The Talos Principle is fixed too. I
think those glitches were actually related to bug 100681. The textures looked
dirty, but they were not complete garbage as seen in the screenshots attached
to this bug. So now I think it is a different problem.

So far I have only seen the glitch on user interface textures.

I am still learning to build my own version of Mesa with a specific version of
LLVM in order to find the bad revision.