You can use a switch in both jams, just wire them in parallel. For example, if your light outlet box contains the supply (hot) cable, you would run a cable from _each_ door switch to that same box. The hot would then be connected to the line side of both switches (pick a wire from each switch), and the load side (the remaining 2 wires) of both switches would be connected to the light. That way either switch will operate the light, and the light will shut off as long as both doors are closed.