[crac] RFR: 8350088: [CRaC] Stop & restart JFR recording on checkpoint [v2]

[Radim Vansa]

> All JFR recordings are closed during checkpoint. After restore JDK starts new recordings with the same parameters as those running before checkpoint. The recordings dumped before checkpoint would be overwritten (as this is a new recording it won't append to the old one).
> If `-XX:StartFlightRecorder=...` is passed on restore a new recording is started.

Radim Vansa has updated the pull request incrementally with one additional commit since the last revision:

  Move Jfr::before_checkpoint() out of VM thread

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Changes:
  - all: https://git.openjdk.org/crac/pull/203/files
  - new: https://git.openjdk.org/crac/pull/203/files/58492f7a..13a34429

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=crac&pr=203&range=01
 - incr: https://webrevs.openjdk.org/?repo=crac&pr=203&range=00-01

  Stats: 4 lines in 1 file changed: 2 ins; 2 del; 0 mod
  Patch: https://git.openjdk.org/crac/pull/203.diff
  Fetch: git fetch https://git.openjdk.org/crac.git pull/203/head:pull/203

PR: https://git.openjdk.org/crac/pull/203