RFR: 8353227: JFR: Prepare tests for strong parser validation

[Markus Grönlund]

Greetings,

Tests:

- jdk/jfr/jvm/TestDumpOnCrash.java
- jdk/jfr/event/runtime/TestShutdownEvent.java

Cannot run with -esa in combination with [JDK-8351698](https://bugs.openjdk.org/browse/JDK-8351698), because parser invariants are not guaranteed for emergency dumps, which are provided on a best-effort basis only.

Testing: jdk_jfr

Thanks
Markus

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Commit messages:
 - 8353227

Changes: https://git.openjdk.org/jdk/pull/24317/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24317&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8353227
  Stats: 38 lines in 2 files changed: 38 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/24317.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24317/head:pull/24317

PR: https://git.openjdk.org/jdk/pull/24317