This reverts commit bb1f71c8.

Summary:
- Replace null with root() to represent root container for consistency
- Support rcm inheritance by Thread.inheritedResourceContainer

Test Plan: jtreg com/alibaba/rcm/ multi-tenent/

Reviewed-by: luchsh, tanghaoth90

Issue: https://github.com/alibaba/dragonwell8/issues/95

Summary: ported TenantDataIsolation to Dragonwell

Test Plan: jdk/test/multi-tenant

Reviewed-by: yuleil, superajun-wsj

Issue: https://github.com/alibaba/dragonwell8/issues/84

Summary: ported MultiTenant framework to Dragonwell8

Test Plan: jdk/test/multi-tenant

Reviewed-by: yuleil, sanhong

Issue: https://github.com/alibaba/dragonwell8/issues/84

Summary:
Introduce ResourceContainer to manage resources.
ResourceContainer defines a set of resource Constraint
that limit resource usage by threads.

Test Plan: jtreg com/alibaba/rcm

Reviewed-by: luchsh, sanhong

Issue: alibaba/dragonwell8#87

8235909: File.exists throws AccessControlException for invalid paths when a SecurityManager is installed
Summary: Backport of JDK-8213429 missed handling the "<<ALL FILES>>" special case
Reviewed-by: mbalao

Summary: G1ElasticHeap to support heap shrink/expansion in runtime

Test Plan:
test/elastic-heap/

Reviewers:
luchsh, sanhong

Issue:
https://github.com/alibaba/dragonwell8/issues/46

CR:
https://github.com/alibaba/dragonwell8_jdk/pull/1

Summary:
Backport of JFR(jdk part) to dragonwell based on JFR preview version(JDK11).
Link:
http://cr.openjdk.java.net/~mgronlun/JEP328_FlightRecorder/Preview/webrev/index.html

Test Plan: test/jdk/jfr/

Reviewers: 卓昂, 传胜, 麦庶, yumin.qi, 三红, 芳玺

Reviewed By: 三红, 芳玺, 卓昂, yumin.qi

Differential Revision: https://aone.alibaba-inc.com/code/D818249

Summary: Finish the job started by 8176536
Reviewed-by: mbalao

Reviewed-by: andrew

Reviewed-by: serb, psadhukhan, mschoene, rhalade

Reviewed-by: dfuchs, chegar, michaelm, rhalade, ahgross

8223163: Better pattern recognition
Reviewed-by: ahgross, bchristi, jeff, rhalade, rriggs, smarks

Reviewed-by: alanb, ahgross, chegar, igerasim

8167646: Better invalid FilePermission
Reviewed-by: mbalao

Reviewed-by: dfuchs, prappo

--HG--
extra : amend_source : 80bdb05e19be5df93a54677d1ef197eb20262d8a

Reviewed-by: igerasim, smarks

8231795: Enhance datagram socket support
Reviewed-by: rriggs, prappo, bpb

Reviewed-by: mbalao

Reviewed-by: chegar, igerasim, ahgross, rhalade

Reviewed-by: ahgross, coffeys, rhalade

Reviewed-by: rriggs, skoivu, ahgross, robm, rhalade, jeff

Reviewed-by: smarks, rriggs, igerasim, ahgross, skoivu, andrew
Contributed-by: NDavid Alvarez <alvdavi@amazon.com>

8209775: ISO 4217 Amendment #169 update
Reviewed-by: naoto, andrew

8202026: ISO 4217 amendment 166
8204269: ISO 4217 amendment 167
Reviewed-by: naoto, andrew
Contributed-by: li.jiang@oracle.com

Reviewed-by: naoto

Reviewed-by: forax, smarks, andrew

Reviewed-by: martin, tvaleev

Summary: Remove ClassLoader.domains
Reviewed-by: coleenp, dholmes, mchung, naoto

Reviewed-by: dl, martin

Reviewed-by: rriggs

Reviewed-by: mbalao

Reviewed-by: andrew

Reviewed-by: skoivu, smarks, rhalade

Reviewed-by: andrew

Reviewed-by: chegar, rhalade, igerasim, bae

Reviewed-by: prr, mschoene, rhalade, psadhukhan

Reviewed-by: xuelei, phh, andrew

Reviewed-by: rriggs, shade

Summary: Change sample code formatting to the currently blessed idiom.
Reviewed-by: martin