RFR: 8302215: G1: Last-ditch Full GC should do serial compaction for tail regions in per thread compaction points. [v6]

[Ivan Walulya]

> Hi all, 
> 
> Please review this change to call `G1FullCollector::phase2c_prepare_serial_compaction` when `do_maximal_compaction`. For maximum compaction, we re-prepare all objects in the "tail" regions of the per thread compaction points.
> 
> Testing: Tier 1-3.
> 
> Thanks

Ivan Walulya has updated the pull request incrementally with one additional commit since the last revision:

  Albert review

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/12529/files
  - new: https://git.openjdk.org/jdk/pull/12529/files/dcb8503f..1b07848b

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=12529&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=12529&range=04-05

  Stats: 20 lines in 2 files changed: 6 ins; 7 del; 7 mod
  Patch: https://git.openjdk.org/jdk/pull/12529.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12529/head:pull/12529

PR: https://git.openjdk.org/jdk/pull/12529