This is a little trickier, we actually open the
`/dev/shm/fex-<pid>-stats` file directly using Windows APIs that way
Mangohud (which is going to be on the Linux side, or potentially even
embedded in to Gamescope) can safely pick up the stats.
A little quirky plus doesn't support expanding its size since WINE
doesn't support NtExtendSection, but that's fine.
