RFR(s): 8222015: Small VM.metaspace improvements

[Thomas Stüfe]

Hi all,

may I have please a review for this collection of small improvements to the
VM.metaspace diagnostic command?

- it clearly marks now classes whose metadata reside in cds
- it shows the number of classes loaded, incl. those from cds, in the
overviews too.

Issue: https://bugs.openjdk.java.net/browse/JDK-8222015
cr:
http://cr.openjdk.java.net/~stuefe/webrevs/8222015--small-vm.metaspace-improvements/webrev.00/webrev/

Example output:
http://cr.openjdk.java.net/~stuefe/webrevs/8222015--small-vm.metaspace-improvements/example-by-spacetype.txt
http://cr.openjdk.java.net/~stuefe/webrevs/8222015--small-vm.metaspace-improvements/example-showloaders.txt
http://cr.openjdk.java.net/~stuefe/webrevs/8222015--small-vm.metaspace-improvements/example-showloaders-showclasses.txt
(scroll
down -> cds classes in <bootstrap> are now marked with 's')

Thank you,

Thomas