RFR: 8360312: Serviceability Agent tests fail with JFR enabled due to unknown thread type JfrRecorderThread [v2]

[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 
> - [x] tier5 ci

Chris Plummer has updated the pull request incrementally with one additional commit since the last revision:

  fix copyright

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/25960/files
  - new: https://git.openjdk.org/jdk/pull/25960/files/a679b236..28a97a11

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=25960&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=25960&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 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