This adds DRI3 1.3 support, which adds the DRI3SetDRMDeviceInUse request. This is just a mirror of the equivalent DRI3 protocol MR: xorgproto!45 (merged)
From that MR's description:
"DRI3SetDRMDeviceInUse is a hint that lets a client tell the server what DRM device it is currently using. This lets the server make more informed decisions for what modifiers to return to the client. This is needed for proper linux dmabuf feedback with Xwayland. Xwayland needs to return a set of modifiers for a particular window for the device that window is using. i.e. if linux_dmabuf feedback advertises a scanout tranche on a device, we need a way to check which device a window is using so we know if we should add that tranche to the window modifiers in the GetSupportedModifiers request."
Please follow up with any protocol design concerns on the xorgproto MR.