[Game]
Middle-Earth: Shadow of Mordor

[Hardware]
AMD R9280, R9270

[Mesa Version]
18.2.4 and 18.2.0 (possibly the entire 18.2 branch)

[Summary of Problem]
The benchmark mode of Middle-Earth: Shadow of Mordor has artifacts in gameplay.
I think this might be related to the rain and I can't find a place in the game
with rain currently but the problem is reproducible in benchmark mode.

[links to images]
Here is a link to some picture of the game in our test suite, the left picture
is the bad one and right is the good: 
https://share.lunarg.com/opengl/report/2404#images/two-up/614953
https://share.lunarg.com/opengl/report/2404#images/two-up/614954