hg: jdk/submit: 8213092: Add more runtime locks for concurrent class unloading

[coleen.phillimore at oracle.com]

Changeset: 6cd56deebb0d
Author:    coleenp
Date:      2018-11-16 10:54 -0500
URL:       http://hg.openjdk.java.net/jdk/submit/rev/6cd56deebb0d

8213092: Add more runtime locks for concurrent class unloading
Summary: Add locks for calling CLDG::purge concurrently as well and for calling SystemDictionary::do_unloading concurrently.
Reviewed-by: eosterlund, hseigel

! src/hotspot/share/classfile/classLoaderData.cpp
! src/hotspot/share/classfile/classLoaderDataGraph.cpp
! src/hotspot/share/classfile/moduleEntry.cpp
! src/hotspot/share/classfile/packageEntry.cpp
! src/hotspot/share/classfile/packageEntry.hpp
! src/hotspot/share/classfile/systemDictionary.cpp