RFR: 8166583: Add oopDesc::klass_or_null_acquire()

[Kim Barrett]

> On Sep 23, 2016, at 3:40 AM, Kim Barrett <kim.barrett at oracle.com> wrote:
> 
>> On Sep 23, 2016, at 3:10 AM, Thomas Schatzl <thomas.schatzl at oracle.com> wrote:
>> Is there a bug filed for fixing the "// Workaround for non-const
>> load_acquire parameter." comment? I.e. it seems that actually more
>> infrastructure changes are required that have been deferred for now.
> 
> Not yet; I’ve drafted it but not actually entered it into the system.  Planning to do that tomorrow.
> 
> I spent a little time working on it, and have a changeset that I think should cover
> it, but I haven’t tested it except locally yet, and can’t test on some affected platforms.
> It touches quite a few files, and is unfortunately less mechanical than one might wish.
> It also doesn’t seem like something that needs to be done for JDK 9.  I’ll probably
> add a pointer to a webrev when I submit the RFE.

https://bugs.openjdk.java.net/browse/JDK-8166651
OrderAccess::load_acquire &etc should have const parameters