[Bug 38178] Crash with Heroes VI at very begin

https://bugs.winehq.org/show_bug.cgi?id=38178

--- Comment #18 from Stefan Dösinger  ---
Created attachment 51099
  --> https://bugs.winehq.org/attachment.cgi?id=51099
wined3d: hack: Don't allow dxt5 textures.

The game tries to use DXT5 textures. We do not support this, and even on
Windows only some drivers have this feature. device_update_volume calculates
the size wrong and the game crashes.

Failing the texture creation call fixes the problem, but unfortunately we
pretend that the call succeeds. The attached hack fixes the crash, but a proper
fix needs more work.