This should hopefully fix some bad indexes. It is possible that a def is temporarily deleted. In that case, we don't want to nuke all of the callers/etc so that if the def is restored we still have that information.
If the def is actually erased it the normal IndexUpdate remove logic will eventually purge the extra state outside of just the def (ie, callers).
- Show base/derived callers ([B] and [D] prefix)
- Show call position information
- Temporarily prevent duplicate calls from appearing, needs a proper fix.