Use the newly introduced Flags<> class to store a bitfield of File::OpenMode in a type-safe way. The existing File::OpenMode enum is renamed to File::OpenModeFlag to free the File::OpenMode for the Flags<> type alias. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>