RFR: 8245233: ZGC: Load volatile oops using Atomic::load()

[Kim Barrett]

> On May 18, 2020, at 3:35 PM, Per Liden <per.liden at oracle.com> wrote:
> 
> Load volatile oops using Atomic::load() rather than using raw dereference.
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8245233
> Webrev: http://cr.openjdk.java.net/~pliden/8245233/webrev.0
> 
> /Per

Looks good.