For L.P. overspeed, read shaft failure.
Most if not all modern electronically controlled engines are prevented from reaching a serious o/s condition by the monitoring. Older engines could be more of a problem in as much as they were 'part throttle' engines, ie, they would give you as much power as you wanted right into an overboost situation (and overspeed!),in this case the only protection would be built into the fuel control unit and it would be a mechanical......err!memory fogging here!! bobweight arrangement. I think P and W called it the speeder spring?? If the engine ever got as far as that though it would have to be pulled! it was there to protect the discs from letting go.