hg: jdk9/dev/jdk: 8175797: (ref) Reference::enqueue method should clear referent before enqueuing

[mandy.chung at oracle.com]

Changeset: bc1bf2be03bc
Author:    mchung
Date:      2017-03-09 07:41 -0800
URL:       http://hg.openjdk.java.net/jdk9/dev/jdk/rev/bc1bf2be03bc

8175797: (ref) Reference::enqueue method should clear referent before enqueuing
Reviewed-by: alanb, kbarrett, mr

! src/java.base/share/classes/java/lang/ref/FinalReference.java
! src/java.base/share/classes/java/lang/ref/Reference.java
! test/java/lang/ref/ReferenceEnqueue.java