Export_info_for_packTransformations on export information that are only used for the building of packs.
val import_for_pack : pack_units:Compilation_unit.Set.t -> pack:Compilation_unit.t -> Export_info.t -> Export_info.tTransform the information from exported to be suitable to be reexported as the information for a pack named pack containing units pack_units. It mainly changes symbols of units pack_units to refer to pack instead.