RFR: 8376956: Add JVMTI phase entering/setting to hserr event log

[Matthias Baesken]

We should add some info to the hserr/hsinfo event logs about JVMTI phases.

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Commit messages:
 - JDK-8376956

Changes: https://git.openjdk.org/jdk/pull/29525/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=29525&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8376956
  Stats: 8 lines in 1 file changed: 7 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/29525.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29525/head:pull/29525

PR: https://git.openjdk.org/jdk/pull/29525