RFR: 8366232: JFR startup messages are shown with -Xlog:jfr+startup=warning [v3]

[Johannes Bechberger]

> Only print the JFR startup messages when no or a < warning log level is set explicitly by the user.

Johannes Bechberger has updated the pull request incrementally with one additional commit since the last revision:

  Rename Atomic:: to AtomicAccess::

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Changes:
  - all: https://git.openjdk.org/jdk/pull/26957/files
  - new: https://git.openjdk.org/jdk/pull/26957/files/56cef57f..4b827459

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=26957&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=26957&range=01-02

  Stats: 3 lines in 1 file changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/26957.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26957/head:pull/26957

PR: https://git.openjdk.org/jdk/pull/26957