RFR: 8209127: ZGC: Improve error message when failing to map memory for mark stacks

[Erik Österlund]

Hi Per,

Looks good.

Thanks,
/Erik

On 2018-08-08 14:14, Per Liden wrote:
> When failing to map memory for mark stacks, we currently always fail 
> with the message "Mark stack overflow", regardless of what the error 
> actually was. We should only say that if we actually exhausted the 
> mark stack space.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8209127
> Webrev: http://cr.openjdk.java.net/~pliden/8209127/webrev.0
>
> /Per