RFR: 7903413: JMH: Safepoint profiler should parse JDK 13+ -Xlog:safepoint

[Aleksey Shipilev]

[JDK-8219436](https://bugs.openjdk.org/browse/JDK-8219436) changed the -Xlog:safepoint logging, and JMH's parser breaks. We need to capture the new format.

Note this was further improved by [JDK-8297154](https://bugs.openjdk.org/browse/JDK-8297154), and needs to be tested with more modern JDKs too.

Additional testing:
 - [x] `-prof safepoints` with JDK 8
 - [x] `-prof safepoints` with JDK 11
 - [x] `-prof safepoints` with JDK 17
 - [x] `-prof safepoints` with JDK 21

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

Commit messages:
 - Fix

Changes: https://git.openjdk.org/jmh/pull/93/files
 Webrev: https://webrevs.openjdk.org/?repo=jmh&pr=93&range=00
  Issue: https://bugs.openjdk.org/browse/CODETOOLS-7903413
  Stats: 27 lines in 1 file changed: 19 ins; 0 del; 8 mod
  Patch: https://git.openjdk.org/jmh/pull/93.diff
  Fetch: git fetch https://git.openjdk.org/jmh pull/93/head:pull/93

PR: https://git.openjdk.org/jmh/pull/93