In the case where a declaration has no type annotation, the interaction
between resolution of `nav_ty` and `nav_val` is a little fiddly because
of the fact that resolving `nav_val` actually implicitly resolves the
type as well. This means `nav_ty` never gets an opporunity to mark its
dependency on the `nav_val`. So, `ensureNavValUpToDate` needs to be the
one to do it. It can't do it too early, though; otherwise, our marking
of dependees as out-of-date/up-to-date will go wrong.

Resolves: #23959