RFR: 8375535: G1: Convert CardTableBarrierSet and subclasses to use Atomic<T>

[Thomas Schatzl]

Hi all,

  use `Atomic<T>` instead of `AtomicAccess` in `CardTableBarrierSet` and subclasses. Since this modifies `CardTableBarrierSet::_card_table` the change has some fan-out.

Testing: gha

Thanks,
  Thomas

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Commit messages:
 - 8375535

Changes: https://git.openjdk.org/jdk/pull/29360/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=29360&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8375535
  Stats: 34 lines in 7 files changed: 5 ins; 0 del; 29 mod
  Patch: https://git.openjdk.org/jdk/pull/29360.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29360/head:pull/29360

PR: https://git.openjdk.org/jdk/pull/29360