RFR(XS) 8224679: Shenandoah: Make ShenandoahParallelCodeCacheIterator noncopyable

[Roman Kennke]

Are there no users of iterator() and cset_iterator()? Or which part am I
missing?

Roman


> Copies may cause its member '_iters' to be freed multiple times.
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8224679
> Webrev: http://cr.openjdk.java.net/~zgu/JDK-8224679/webrev.00/
> 
> Test:
>   hotspot_gc_shenandoah (fastdebug and release)
> 
> Thanks,
> 
> -Zhengyu