Any chance VALVe introduced this? They won't admit it.
https://github.com/ValveSoftware/steam-for-linux/issues/4409

The patches attatched here are present in Linux 4.6. I tested linux-git-4.7-rc7
with mesa-git-12.1 compiled against llvm-snv-3.9, and TF2 still crashes.

Setting every graphical option to Low doesn't help.