As _WINE_HWND_STYLE and _WINE_HWND_EXSTYLE respectively.
Gamescope parses these to make smarter decisions about what window to primary focus, or to treat as a dropdown/overlay.
This was originally a Proton commit by Remi Bernon, however, it would definitely be nice to have support for Gamescope focusing correctly under upstream Wine as well.
Fixes a bunch of games/launchers run with Wine under Gamescope.