RFR: 8337317: serviceability/jvmti tests failed with FATAL ERROR in native method: Failed during the GetClassSignature call

[Alex Menkov]

The fix adds guards against JVMTI_ERROR_WRONG_PHASE error in event handlers

Testing: hotspot/jtreg/serviceability/jvmti on all platforms

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

Commit messages:
 - fix

Changes: https://git.openjdk.org/jdk/pull/20699/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20699&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8337317
  Stats: 89 lines in 2 files changed: 86 ins; 1 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/20699.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20699/head:pull/20699

PR: https://git.openjdk.org/jdk/pull/20699