DmdAnal: Unleash demand signatures of free RULE and unfolding binders (#23208)
In #23208 (closed) we observed that the demand signature of a binder occuring in a RULE wasn't unleashed, leading to a transitively used binder being discarded as absent. The solution was to use the same code path that we already use for handling exported bindings.
See the changes to Note [Absence analysis for stable unfoldings and RULES]
for more details.
Fixes #23208 (closed).