Fix crash introduced by LLInstanceTrackerBase optimization.  Reviewed by Kelly
Fix crash introduced by LLInstanceTrackerBase optimization.  Reviewed by Kelly

gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm