RFR(XXS): 8206254: Unable to complete emergency dump during safepoint

[Erik Gahlin]

Looks good.

Erik

> Greetings,
>
> Please review this small adjustment in order to allow writing an emergency dump from within a safepoint context.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8206254
> Webrev: http://cr.openjdk.java.net/~mgronlun/8206254/webrev00/
>
> Thanks
> Markus