I think the strings will break before you damage the neck, but not sure. Usually, tuning up or down is a balancing act with the string gauges -- once you tune beyond a whole step or so, you'll want to change the string gauges to make it feel the same playing.
Also, you may render the guitar unplayable by increasing the tension too high by tuning up without changing strings to a new gauge -- it'll just be too hard to fret the strings beyond a certain tension. Have you ever played 12s or 13s on a regular scale length 6-string guitar?
You certainly will not damage the neck by tuning up while also changing to new string gauges, although you may have trouble finding 9s long enough (not sure about that neither). The choices with baritone length strings are pretty limited, and I'm not sure regular guitar strings will be long enough.