RFR: 8360287: JFR: PlatformTracer class should be loaded lazily

[Erik Gahlin]

Could I have a review of a change that ensures that the PlatformTracer and its static initializers are not run unless a method timing or method tracing filter has been set?

Testing: test/jdk/jdk/jfr

Thanks
Erik

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Commit messages:
 - Remove whitespace
 - Initial

Changes: https://git.openjdk.org/jdk/pull/25937/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25937&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8360287
  Stats: 75 lines in 4 files changed: 62 ins; 11 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/25937.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25937/head:pull/25937

PR: https://git.openjdk.org/jdk/pull/25937