RFR: 7903511: JMH: Add score stability performance tests

[Aleksey Shipilev]

For machines in the clouds, it is important to quantify whether their long-term performance deviates. This is important for any benchmarking to make sense.

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Commit messages:
 - Work

Changes: https://git.openjdk.org/jmh/pull/116/files
 Webrev: https://webrevs.openjdk.org/?repo=jmh&pr=116&range=00
  Issue: https://bugs.openjdk.org/browse/CODETOOLS-7903511
  Stats: 163 lines in 5 files changed: 155 ins; 0 del; 8 mod
  Patch: https://git.openjdk.org/jmh/pull/116.diff
  Fetch: git fetch https://git.openjdk.org/jmh.git pull/116/head:pull/116

PR: https://git.openjdk.org/jmh/pull/116