RFR: 8335836: serviceability/jvmti/StartPhase/AllowedFunctions/AllowedFunctions.java fails with unexpected exit code: 112 [v4]

[Serguei Spitsyn]

> The test has been fixed to:
>  - add a guard against JVMTI_ERROR_WRONG_PHASE
>  - replace `exit(err)` with `abort()` in the `check_jvmti_error()`
>  
> The JVMTI `VMDeath` event is enabled and a `RawMonitor` is introduced to serialize `ClassPrepare` and `VMDeath` events, and so, to prevent JVMTI_ERROR_WRONG_PHASE in the `ClassPrepare` events.
> 
> Testing:
>  - run the test AllowedFunctions.java locally
>  - TBD: submit a mach5 run for fixed test

Serguei Spitsyn has updated the pull request incrementally with one additional commit since the last revision:

  tweeked comment in ClassPrepare event callback

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/20397/files
  - new: https://git.openjdk.org/jdk/pull/20397/files/4cf09f7b..2a0c56b6

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20397&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20397&range=02-03

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/20397.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20397/head:pull/20397

PR: https://git.openjdk.org/jdk/pull/20397