RFR: 8342818: Implement CPU Time Profiling for JFR

[Johannes Bechberger]

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

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Commit messages:
 - Use try-with-resources in tests
 - Fix stackTrace setting issue
 - Fix threshold setting issue
 - Add missing files
 - Simplify rate parsing
 - Small fixes
 - Small build fix for non-Linux
 - Small clean up
 - Change thread and weight name
 - Add missing files
 - ... and 113 more: https://git.openjdk.org/jdk/compare/b6700095...366aced5

Changes: https://git.openjdk.org/jdk/pull/20752/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20752&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8342818
  Stats: 2350 lines in 48 files changed: 2147 ins; 176 del; 27 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