...but not in the way you'd expect. We were actually tracking them in
cases where we shouldn't have been! We cannot track a declaration if its
parent namespace has been lost, because that will cause analysis
failures immediately, but if we excluded a type from the mapping due to
a major change (such as a struct turning into a union, or a field being
added), we were still including any trackable instructions inside the
container's field expressions (e.g. struct field type expressions). This
meant we were tracking a type declaration while losing tracking on its
parent namespace, with predictably disastrous results.
Oh, also, tracking for opaque types was just totally wrong (I think this
was a typo from a while back). We could map it to things other than
opaque declarations, and we never mapped declarations inside opaques.
So, uh, I fixed that too.