In 5917 I've again come up with a use for moving
As far as I can tell it doesn't really depend on anything in
ide_db. Would this be accepted?
Definition is intentionally in IDE -- on the hir level, it doesn't make sense to treat locals & modules the same, for example. On the hir layer, you generally know what kind of definition you can work with.
A generic "any" definition is useful on the IDE layer to implement Goto Definition and such.