Fix a pg_dump output ordering problem introduced in 8.3 by the addition of

array types for composite types.  Although pg_dump understood it wasn't
supposed to dump these array types as separate objects, it must include
them in the dependency ordering analysis, and it was improperly assigning them
the same relatively-high sort priority as regular types.  This resulted in
effectively moving composite types and tables up to that same high priority,
which broke any ordering requirements that weren't explicitly enforced by
dependencies.  In particular user-defined operator classes, which should come
out before tables, failed to do so.  Per report from Brendan Jurd.

In passing, also fix an ill-considered decision to give text search objects
the same sort priority as functions and operators --- the sort result looks
a lot nicer if different object types are kept separate.  The recent
foreign-data patch had copied that decision, making the sort ordering even
messier :-(