NVIDIA-software may check the environment variable `NVIDIA_WINE_DLL_DIR`
for a path where DLLs provided by the NVIDIA Linux driver can be found.
This is done as a fallback for when the "DriverStore" cannot be detected
via the D3DDDI functions for querying an adapter-specific registry key.

Tested with an application that reads `NVIDIA_WINE_DLL_DIR` from the
environment and tries to load a known DLL from it. As expected manually
setting the environment variable to the on-disk location did not work,
as the path is not accurate within the pressure-vessel environment.