swift234

IRGen: Use NecessaryBindings to save captured generic context into partial_apply closures.

In order to deal with generic indirect value captures, we need to be able to bind their type metadata in the partial apply forwarder and heap object destructor to have access to the value operations for that type. NecessaryBindings gives us a way to do that and clean up our ad-hoc polymorphic argument forwarding we had before. N(intended)FC yet, aside from some harmless reordering of operations, since we also need to implement NonFixedOffsets for heap objects to be fully operational.

Swift SVN r24526