hg: jdk9/sandbox/hotspot: Add support for a reachability fence.

[paul.sandoz at oracle.com]

Changeset: bf51b52a898d
Author:    psandoz
Date:      2015-10-06 18:37 +0200
URL:       http://hg.openjdk.java.net/jdk9/sandbox/hotspot/rev/bf51b52a898d

Add support for a reachability fence.
Contributed-by: dl at cs.oswego.edu, aleksey.shipilev at oracle.com, paul.sandoz at oracle.com

! src/share/vm/classfile/vmSymbols.cpp
! src/share/vm/classfile/vmSymbols.hpp
! src/share/vm/oops/method.cpp