Summary: @public Completely removes the usage of weak JNI refs. This is great, because node allocation and deallocation no longer go through a VM-global lock to access the weak reference table. This is also great, because we can no longer overflow that ref table. Performance is comparable to weak refs. Reviewed By: marco-cova Differential Revision: D14423068 fbshipit-source-id: 62003d2d6fd971e91460a26fb3477046f26e2ba5