The system is Gentoo, this problem tested on the latest stable version of
mesa/llvm/kernel and latest git versions. 

It's a very popular report for game developers
https://forum.paradoxplaza.com/forum/index.php?threads/surviving-mars-graphical-artifacts-on-game-map-linux.1121318/

Affectect all amdgpu cards, my own is vega56. 

With R600_DEBUG=nir this bug is gone but I my system start unstable and time to
time GPU hangs occurred. 

I suppose it's same problem as with Civ VI
https://bugs.freedesktop.org/show_bug.cgi?id=104602

I will try Arceri patch to check it.