Blender crashes when rendering a scene that has a file output node with
no inputs. That's because the preview code assumes that nodes would
always have inputs. So we simply guard against this case.
By now it is just a "compositor", so move the files one folder up.
Things that were under realtime_compositor/intern move into
already existing intern folder.
Pull Request: https://projects.blender.org/blender/blender/pulls/132004