RFR: 8375438: G1: Convert G1HeapRegion related classes to use Atomic<T> [v2]

[Thomas Schatzl]

> Hi all,
> 
>   please review conversion of G1HeapRegion related classes to use Atomic<T>.
> 
> Testing: tier1, tier4, tier5
> 
> (The PipelineLeaksFD failure in gha is a known issue)
> 
> Thanks,
>   Thomas

Thomas Schatzl has updated the pull request incrementally with one additional commit since the last revision:

  * shade review

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/29301/files
  - new: https://git.openjdk.org/jdk/pull/29301/files/636c7a7b..2a18c2eb

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=29301&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=29301&range=00-01

  Stats: 8 lines in 2 files changed: 3 ins; 2 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/29301.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29301/head:pull/29301

PR: https://git.openjdk.org/jdk/pull/29301