This reverts commit 5382b8e0.

Reviewers: 效山, 芳玺, 传胜, 三红, yumin.qi

Reviewed By: 三红, 芳玺, 效山, 卓仁

Differential Revision: https://aone.alibaba-inc.com/code/D815657

Reviewed-by: dholmes, ehelin

Reviewed-by: dholmes, ehelin

Reviewed-by: mgerdin, stefank

Reviewed-by: sla, stefank

Reviewed-by: mgerdin, coleenp, bdelsart

8047812: Ensure ClassLoaderDataGraph::classes_unloading_do only delivers klasses from CLDs with non-reclaimed class loader oops
Reviewed-by: coleenp, sspitsyn, ehelin

Reviewed-by: tschatzl, ehelin, brutisso, coleenp, roland, iveresov
Contributed-by: stefan.karlsson@oracle.com, mikael.gerdin@oracle.com

Summary: Only prune metaspace virtual spaces at safepoint so walking them is safe outside a safepoint.
Reviewed-by: mgerdin, mgronlun, hseigel, stefank

Reviewed-by: coleenp, mgerdin

Summary: Remove search in system dictionary and hacks, replace with verifying in CLD::_klasses list.
Reviewed-by: dcubed, acorn

8047812: Ensure ClassLoaderDataGraph::classes_unloading_do only delivers klasses from CLDs with non-reclaimed class loader oops
Reviewed-by: coleenp, sspitsyn, ehelin

Summary: Metaspace::contains cannot look at purged metaspaces while CMS concurrently deallocates them.
Reviewed-by: mgerdin, sspitsyn, jmasa

Reviewed-by: dholmes, egahlin

Summary: Rewrite of the getLoadedClasses() method implementation to include anonymous classes.
Reviewed-by: coleenp, sspitsyn

Reviewed-by: acorn, coleenp, sla
Contributed-by: NKaren Kinnear &lt;karen.kinnear@oracle.com&gt;, Bengt Rutisson &lt;bengt.rutisson@oracle.com&gt;, Calvin Cheung &lt;calvin.cheung@oracle.com&gt;, Erik Gahlin &lt;erik.gahlin@oracle.com&gt;, Erik Helin &lt;erik.helin@oracle.com&gt;, Jesper Wilhelmsson &lt;jesper.wilhelmsson@oracle.com&gt;, Keith McGuigan &lt;keith.mcguigan@oracle.com&gt;, Mattias Tobiasson &lt;mattias.tobiasson@oracle.com&gt;, Markus Gronlund &lt;markus.gronlund@oracle.com&gt;, Mikael Auno &lt;mikael.auno@oracle.com&gt;, Nils Eliasson &lt;nils.eliasson@oracle.com&gt;, Nils Loodin &lt;nils.loodin@oracle.com&gt;, Rickard Backman &lt;rickard.backman@oracle.com&gt;, Staffan Larsen &lt;staffan.larsen@oracle.com&gt;, Stefan Karlsson &lt;stefan.karlsson@oracle.com&gt;, Yekaterina Kantserova <yekaterina.kantserova@oracle.com>

Summary: Move initialization of dependencies to before allocation of CLD
Reviewed-by: stefank, coleenp

Summary: Refactor the CLD dependency list into a separate class. Use an ObjectLocker to synchronize additions to the CLD dependency list.
Reviewed-by: stefank, coleenp

Reviewed-by: kvn, jrose

Summary: SystemDictionary::find(...) should not create and register ClassLoaderData objects for class loaders.
Reviewed-by: coleenp, acorn
Contributed-by: NStefan Karlsson &lt;stefan.karlsson@oracle.com&gt;, Erik Helin <erik.helin@oracle.com>

Summary: Restructure initialization of ClassLoaderData to not add a new instance if init_dependencies fail
Reviewed-by: stefank, coleenp

Summary: jcmd <pid> GC.class_stats (UnlockDiagnosticVMOptions)
Reviewed-by: coleenp, hseigel, sla, acorn
Contributed-by: ioi.lam@oracle.com

Reviewed-by: ohair

Summary: Add klass_holder() to return either mirror or class_loader depending on if the class is anonymous or not.
Reviewed-by: stefank, jrose

Summary: Add ClassLoaderData object for each anonymous class with metaspaces to allocate in.
Reviewed-by: twisti, jrose, stefank

Reviewed-by: stefank, coleenp, kvn

Summary: Remove PermGen, allocate meta-data in metaspace linked to class loaders, rewrite GC walking, rewrite and rename metadata to be C++ classes
Reviewed-by: jmasa, stefank, never, coleenp, kvn, brutisso, mgerdin, dholmes, jrose, twisti, roland
Contributed-by: Njmasa &lt;jon.masamitsu@oracle.com&gt;, stefank &lt;stefan.karlsson@oracle.com&gt;, mgerdin &lt;mikael.gerdin@oracle.com&gt;, never <tom.rodriguez@oracle.com>