RFR: 8274191: Improve g1 evacuation failure injector performance

[Thomas Schatzl]

Hi all,

  can I have reviews for this change that improves evacuation failure injector performance to be usable for pinned region performance work?

The suspected reason I think why performance is so bad (image in the CR), is that the unsynchronized reads and writes to `G1YoungGCEvacFailureInjector::_evacuation_failure_object_count` cause massive performance issue if done millions of times.

This change makes that counter thread-local, fixing that issue completely.

I initially had a prototype using a `THREAD_LOCAL`, but when testing I had the feeling that this is/was slightly slower and I thought that adding a variable to every thread where most do not use them seems to be a waste.

Testing: local testing, GHA

Thanks,
  Thomas

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Commit messages:
 - Fixes
 - Make injector counter local

Changes: https://git.openjdk.java.net/jdk/pull/5650/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5650&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8274191
  Stats: 34 lines in 5 files changed: 17 ins; 8 del; 9 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5650.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5650/head:pull/5650

PR: https://git.openjdk.java.net/jdk/pull/5650