8207778: Add locking to ModuleEntry and PackageEntry tables
Summary: Restructure ClassLoaderDataGraph code to simplify using locks in SystemDictionary::do_unloading()
Reviewed-by: lfoltan, coleenp
^build/
^dist/
^.idea/
nbproject/private/
^webrev
^.src-rev$
^.jib/
\.DS_Store
\.metadata/
\.recommenders/
test/nashorn/script/external
test/nashorn/lib
NashornProfile.txt
.*/JTreport/.*
.*/JTwork/.*
.*/.git/.*