RFR: 8268398: 15% increase in JFR footprint in Noop-Base

[Erik Gahlin]

Hi,

Could I have review of a PR that skips bytecode instrumentation for container events and initialisation of Container.metrics() if the JVM is isn't running in a container, or to be precise, if container support is not available. If a user specifies -XX:-UseContainerSupport, events are not emitted. This was the case before this PR, and maybe it should be fixed, but it's an enhancement and outside the scope of this bug.

Testing:
- jdk/jdk/jfr
- Manual testing in a container.

I tried to run test/hotspot/jtreg/containers/docker/TestJFREvents.java, but the test is broken (image can't be built, so test is skipped). 

This fix may not be sufficient to reduce footprint introduced by the container events, but [JDK-8282420: JFR: Remove event handlers](https://bugs.openjdk.org/browse/JDK-8282420) also reduced number of loaded classes which should reduce footprint in JDK 19. There are an ongoing enhancement work to generate bytecode and metadata at build time, which will help, but it will be integrated in JDK 20. 

Thanks
Erik

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Commit messages:
 - Initial

Changes: https://git.openjdk.org/jdk19/pull/31/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk19&pr=31&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8268398
  Stats: 55 lines in 8 files changed: 40 ins; 5 del; 10 mod
  Patch: https://git.openjdk.org/jdk19/pull/31.diff
  Fetch: git fetch https://git.openjdk.org/jdk19 pull/31/head:pull/31

PR: https://git.openjdk.org/jdk19/pull/31