swift234

SILGen: Update Erasure- and ArchetypeToSuperExpr.
Now that we can represent address-only values, SILGen can correctly generate these operations in terms of archetype/existential addresses instead of impossible values. archetype_to_super is slightly tricky since we can forward ownership from the address-only derived value to the loadable base value, which is normally prevented by the ManagedValue interface, so I wrote some special-case logic directly into visitArchetypeToSuperExpr to handle forwarding the cleanup. Reenable some disabled checks in the expressions test for things that work again.

Swift SVN r3566