RFR: 8373439: Deadlock between flight recorder & VMDeath [v2]

[Bara' Hasheesh]

> A simple `PlatformRecorder.isInShutDown` check is added to `PlatformRecording.start` to prevent any new recording from start after the JVM initiates it's shutdown hooks  
> 
> A new test was added that fails without the change & passes with it 
> 
> I also ran `tier1`, `tier2` as well as `jdk_jfr` on Linux x86

Bara' Hasheesh has updated the pull request incrementally with one additional commit since the last revision:

  flags

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Changes:
  - all: https://git.openjdk.org/jdk/pull/28767/files
  - new: https://git.openjdk.org/jdk/pull/28767/files/d1eec7c3..e8811e0f

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=28767&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=28767&range=00-01

  Stats: 65 lines in 4 files changed: 53 ins; 6 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/28767.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28767/head:pull/28767

PR: https://git.openjdk.org/jdk/pull/28767