RFR: 7903510: JMH: Add core performance checking tests

[Aleksey Shipilev]

In JMH Core benchmarks, we would like to make sure that every core on the machine is symmetric. This is important for single-threaded benchmarks to make sense.

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

Commit messages:
 - Fix

Changes: https://git.openjdk.org/jmh/pull/117/files
 Webrev: https://webrevs.openjdk.org/?repo=jmh&pr=117&range=00
  Issue: https://bugs.openjdk.org/browse/CODETOOLS-7903510
  Stats: 142 lines in 3 files changed: 142 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jmh/pull/117.diff
  Fetch: git fetch https://git.openjdk.org/jmh.git pull/117/head:pull/117

PR: https://git.openjdk.org/jmh/pull/117