Theoretically, could a Mine Clearing Line Charge be used to demolish buildings?

Theoretically; yes. But, it would be far from the best option.

Mine clearing explosives give a large push at a distance so that mines in the blast area receive enough pressure to trigger.

Building demolition is about cutting (shearing) pressures that stay precisely in their intended area to reduce any unintended results.

In short, its sledgehammer when you only need a tack hammer. It will work, but the additional damage may not be worth it.