RFR: 8224962: ZGC: Strengthen ZHeap::is_oop()

[Erik Österlund]

Hi Per,

Looks good.

/Erik

On 2019-05-29 11:26, Per Liden wrote:
> ZHeap::is_oop() currently only verifies that the metadata bits are 
> good. However, we should also check that non-offset and non-metadata 
> bits are not set.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8224962
> Webrev: http://cr.openjdk.java.net/~pliden/8224962/webrev.0
>
> /Per