This enhancement changes phantom references to be automatically cleared by the garbage collector as soft and weak references.

An object becomes phantom reachable after it has been finalized. This change may cause the phantom reachable objects to be GC'ed earlier - previously the referent is kept alive until PhantomReference objects are GC'ed or cleared by the application. This potential behavioral change might only impact existing code that would depend on PhantomReference being enqueued rather than when the referent be freed from the heap.