RFR: 8360312: Serviceability Agent tests fail with JFR enabled due to unknown thread type JfrRecorderThread

[Chris Plummer]

Update SA to know about JfrRecorderThread, which was made a JavaThread in JDK 25 by [JDK-8352251](https://bugs.openjdk.org/browse/JDK-8352251).

I'm also fixing ClhsdbJstackWithConcurrentLock, which was also failing with JFR enabled, but for a different reason (specified heap size was too small).

Testing (in progress):

- [x] tier1 ci
- [x] tier1 ci with -XX:StartFlightRecording 
- [ ] tier5 ci

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Commit messages:
 - revisit my ABC's
 - Make JfrRecorderThread known to SA

Changes: https://git.openjdk.org/jdk/pull/25960/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25960&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8360312
  Stats: 25 lines in 5 files changed: 13 ins; 9 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/25960.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25960/head:pull/25960

PR: https://git.openjdk.org/jdk/pull/25960