RFR: 8374350: Convert hotspot gtests to use Atomic<T> [v2]

[Kim Barrett]

> Please review this change to convert HotSpot gtests to use Atomic<T> rather
> than directly using AtomicAccess.
> 
> test_atomicAccess.cpp is, of course, not subject to this conversion.
> 
> test_globalCounter.cpp is also not included in this conversion.  The other
> conversions were straight forward.  This test is less so, and I decided I
> needed to spend more time studying it, so have left it for followup work.
> 
> The conversion of each test is a separate commit, in case that makes it easier
> to review.
> 
> Testing: mach5 tier1

Kim Barrett has updated the pull request incrementally with one additional commit since the last revision:

  update copyrights

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/29001/files
  - new: https://git.openjdk.org/jdk/pull/29001/files/a98a1b6b..8f35f5c8

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=29001&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=29001&range=00-01

  Stats: 9 lines in 9 files changed: 0 ins; 0 del; 9 mod
  Patch: https://git.openjdk.org/jdk/pull/29001.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29001/head:pull/29001

PR: https://git.openjdk.org/jdk/pull/29001