swift234

Archetypes with superclass bounds are class-bounded.

Treat archetypes with a superclass bound as class-bounded. Change SILGen and IRGen to use the new SuperToArchetypeRef and ArchetypeRefToSuper cast instructions, and drop the old SuperToArchetype and ArchetypeToSuper instructions, which are unneeded because any archetype with a superclass will be class-bounded.

Note that this patch doesn't implement representation optimization for archetypes with superclass bounds--they're still always represented with a worst-case UnknownRefCountedPtrTy.

Swift SVN r5629