RFR: 8205338: ZGC: LeakProfiler not yet supported

[Erik Gahlin]

Looks good.

Erik

> Disable JFR's LeakProfiler when using ZGC. There are a number of 
> reasons why this doesn't work yet. The LeakProfiler doesn't use the 
> access API, does it's own root scanning, allocates a bitmap spanning 
> the entire revered range, etc.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8205338
> Webrev: http://cr.openjdk.java.net/~pliden/8205338/webrev.0
>
> /Per