swift234

DI: New way of modeling factory initializers

Previously, we were only able to detect factory initializers
dispatched through class_method. This didn't work for
factory initializers defined in protocol extensions.

The end result would be that we would strong_release an
uninitialized class instance, which could cause crashes.

Fix DI to correctly release the old instance using
dealloc_partial_ref instead.

Fixes <rdar://problem/27713221>.