Summary: G1ElasticHeap to support heap shrink/expansion in runtime

Test Plan:
test/elastic-heap/

Reviewers:

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

CR:
https://github.com/alibaba/dragonwell8_hotspot/pull/12

Summary:
- port D64010 to dragonwell
- print the detail time when doing root processing in generational heap collection

Test Plan:
hotspot/test/gc/TestPrintGCRootsTraceTime.java
hotspot/test/gc/

Reviewers: 传胜

Differential Revision: https://aone.alibaba-inc.com/code/D851700

Summary:
- Port D65580 to dragonwell
- Print the young generation histogram once after parnew gc with the manageable flag: PrintYoungGenHistoAfterParNewGC

Test Plan: hotspot/test/gc/parNew/testPrintYoungGenHisto.sh

Reviewers: 传胜

Differential Revision: https://aone.alibaba-inc.com/code/D849729

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: kbarrett, tschatzl

Summary: Speed up ParNew collections by pruning the list of scavengable nmethods.
Reviewed-by: jmasa, tonyp, twisti

Reviewed-by: tschatzl

Reviewed-by: dholmes

8204872: [8u] VS2017: more instances of "error C3680: cannot concatenate user-defined string literals with mismatched literal suffix identifiers"
Reviewed-by: dholmes

Summary: Use the initial active processor count for memory initialization instead of the current active one.
Reviewed-by: dholmes, mgerdin

Summary: Use the initial active processor count for memory initialization instead of the current active one.
Reviewed-by: dholmes, mgerdin

Summary: Use the initial active processor count for memory initialization instead of the current active one.
Reviewed-by: dholmes, mgerdin

Reviewed-by: simonis, tschatzl, mgerdin, dlong
Contributed-by: gunter.haug@sap.com

Summary: Putting a comma after the year in GPL header.
Reviewed-by: dholmes, tschatzl

Reviewed-by: tschatzl, sjohanss

Summary: Fix memory overuse in g1CodeCacheRemset
Reviewed-by: tschatzl

Summary: Add os::vsnprintf and os::snprintf.
Reviewed-by: kbarrett, lfoltan, stuefe, mlarsson

Summary: Before processing an element in the non-shared overflow buffer, try to push it into the local shared buffer to keep it full.
Reviewed-by: jmasa, ehelin, sjohanss

Reviewed-by: pliden, tschatzl

Summary: Before processing an element in the non-shared overflow buffer, try to push it into the local shared buffer to keep it full.
Reviewed-by: jmasa, ehelin, sjohanss

Summary: Typo error referring new_acitve_workers is corrected as new_active_workers
Reviewed-by: jmasa, drwhite
Contributed-by: fairoz.matte@oracle.com

Reviewed-by: mgerdin, tschatzl
Contributed-by: richard.reingruber@sap.com

8076995: gc/ergonomics/TestDynamicNumberOfGCThreads.java failed with java.lang.RuntimeException: 'new_active_workers' missing from stdout/stderr
Reviewed-by: jmasa, drwhite

Reviewed-by: tschatzl, mgerdin, kbarrett, drwhite

Summary: Adding missing check for valid oop.
Reviewed-by: dcubed
Contributed-by: NShafi Ahmad <shafi.s.ahmad@oracle.com>

Reviewed-by: stuefe, coleenp, roland

Summary: Implement remembered sets verification for G1 with option VerifyRememberedSets
Reviewed-by: jmasa, mgerdin

Summary: Do not make reused PRTs available to other threads before the bitmap of the PRT has been cleared.
Reviewed-by: tbenson, mgerdin, brutisso
Contributed-by: NPoonam Bajaj &lt;poonam.bajaj@oracle.com&gt;, Thomas Schatzl <thomas.schatzl@oracle.com>

8139424: SIGSEGV, Problematic frame: # V [libjvm.so+0xd0c0cc] void InstanceKlass::oop_oop_iterate_oop_maps_specialized<true,oopDesc*,MarkAndPushClosure>
Summary: The crash was caused by a faulty eager humongous reclaim. The reason for reclaiming a live object was that the call to cleanupHRRS was done after dirtying cards and clearing the remembered sets for the humongous object. This could lead to one or many cards being missed.
Reviewed-by: tbenson, kbarrett, tschatzl

Reviewed-by: mgerdin, vlivanov

Reviewed-by: jwilhelm, jmasa

Summary: Add a WhiteBox callback to the VM to start a concurrent mark cycle in G1.
Reviewed-by: tschatzl, sjohanss
Contributed-by: NLeonid Mesnik <leonid.mesnik@oracle.com>

Summary: Add SO_AllCodeCache to root scanning options when not unloading classes with a CMS collection cycle
Reviewed-by: mgerdin, jwilhelm

Summary: Fix up GPL headers so that the RE script works.
Reviewed-by: stefank, dholmes, coleenp

8061715: gc/g1/TestShrinkAuxiliaryData15.java fails with java.lang.RuntimeException: heap decommit failed - after > before
Summary: added WhiteBox methods to count regions and exact aux data sizes
Reviewed-by: jwilhelm, brutisso

Summary: Don't assume SATB buffer entries are valid objects
Reviewed-by: brutisso, ecaspole

Summary: Removed no longer valid checking of SATB buffers
Reviewed-by: jmasa, pliden

Summary: Apply closure directly, eliminating registration.
Reviewed-by: stefank, tschatzl

Summary: Removed pre-filter verify, and made filtering more careful.
Reviewed-by: brutisso, tschatzl

Summary: Prevent eager reclaim of objects that might be on mark stack.
Reviewed-by: brutisso, tschatzl