This was caused by 72b172bdf6 in #121206. That commit removed an early
return from `analysis` when there are stashed errors. As a result, it's
possible to reach privacy analysis when there are stashed errors, which
means more code paths can be reached. One such code path was handled in
that commit, where a `span_bug` was changed to a `span_delayed_bug`.
This commit handles another such code path uncovered by fuzzing, in much
the same way.
Fixes#121455.
21bb1a4359