[8u] RFA 8031304 : Add dcmd to print all loaded dynamic libraries

[David Buck]

Hi!

Please approve this serviceability backport to 8u-dev:

bug report:
https://bugs.openjdk.java.net/browse/JDK-8031304

JDK 9 changeset:
http://hg.openjdk.java.net/jdk9/jdk9/hotspot/rev/afa21611f918

JDK 9 review thread:
http://mail.openjdk.java.net/pipermail/serviceability-dev/2014-January/013778.html

JDK 8 backport review thread:
http://mail.openjdk.java.net/pipermail/serviceability-dev/2017-December/022677.html

JDK 8 backport webrev (already reviewed):
http://cr.openjdk.java.net/~dbuck/8031304_jdk8_ver00/

Cheers,
-Buck