Since 02ee5a7693 we cant call `ED_view3d_win_to_ray_clipped_ex` with
null `r_ray_end`, `ED_view3d_clip_segment` relies on it.
To fix this, just pass a dummy from `ED_view3d_win_to_ray_clipped`.
Pull Request: https://projects.blender.org/blender/blender/pulls/115840