mkTreeInfoHoisted is slow

[aakropotkin]

mkTreeInfoHoisted is unreasonably slow to the point of being unusable for any project larger than ~150 modules.

A rough list of things that could be optimized here are:

1. subScopeHoisted could ignore dependencies which are already in scope. Modifying the pred function could help here.
2. Using pdefClosureFunctorCached could eliminate redundant collections of closures in subScopeHoisted.
3. General reduction in usage of modules/types for internal operations.