hg: jdk9/dev/jdk: 8145459: Cleaner - use Reference.reachabilityFence

[roger.riggs at oracle.com]

Changeset: 1f33e517236e
Author:    rriggs
Date:      2016-01-20 11:33 -0500
URL:       http://hg.openjdk.java.net/jdk9/dev/jdk/rev/1f33e517236e

8145459: Cleaner - use Reference.reachabilityFence
Reviewed-by: psandoz, mchung, chegar

! src/java.base/share/classes/jdk/internal/ref/PhantomCleanable.java
! src/java.base/share/classes/jdk/internal/ref/SoftCleanable.java
! src/java.base/share/classes/jdk/internal/ref/WeakCleanable.java