RFR: 8342818: Implement CPU Time Profiling for JFR [v6]

[Johannes Bechberger]

> This is the code for the [JEP draft: CPU Time based profiling for JFR].

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

  Add worker thread id getter to whitebox

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/20752/files
  - new: https://git.openjdk.org/jdk/pull/20752/files/1e0dbaea..01783bc9

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20752&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20752&range=04-05

  Stats: 34 lines in 4 files changed: 33 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/20752.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20752/head:pull/20752

PR: https://git.openjdk.org/jdk/pull/20752