RFR 8249837: Avoid direct or implicit Thread::current() calls when we already have a current thread variable

[coleen.phillimore at oracle.com]

On 7/29/20 11:54 AM, coleen.phillimore at oracle.com wrote:
> Summary: Add current thread and/or moved HandleMark to the scope that 
> it is needed
>
> This patch removes HandleMarks from the GC code.  I added a 
> NoHandleMark to these places and found the locations in the 
> verification code that needs the HandleMarks, and moved them there.

Also Universe::verify() already has a HandleMark, so these are removed 
from the GC code also.

>
> Tested with tier1-6 with no failures.
>
> open webrev at http://cr.openjdk.java.net/~coleenp/2020/8249837.01/webrev
> bug link https://bugs.openjdk.java.net/browse/JDK-8249837
>
> Thanks,
> Coleen