RFR: 8370389: JavaFrameAnchor on s390 has unnecessary barriers

[Amit Kumar]

No hardware barriers are necessary. All members are volatile and the profiler is run from a signal handler.

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Commit messages:
 - remove barriers

Changes: https://git.openjdk.org/jdk/pull/27930/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27930&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8370389
  Stats: 19 lines in 1 file changed: 5 ins; 11 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/27930.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27930/head:pull/27930

PR: https://git.openjdk.org/jdk/pull/27930