RFR: CODETOOLS-7903487: JMH: Cover JMH profilers with basic tests [v5]

[Aleksey Shipilev]

> JMH profilers is the important feature, and they should be verified with at least smoke tests to capture their breakage, e.g. when JDK changes something.

Aleksey Shipilev has updated the pull request incrementally with two additional commits since the last revision:

 - More profiler touchups
 - Touchups

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Changes:
  - all: https://git.openjdk.org/jmh/pull/109/files
  - new: https://git.openjdk.org/jmh/pull/109/files/d4eff046..8225264b

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jmh&pr=109&range=04
 - incr: https://webrevs.openjdk.org/?repo=jmh&pr=109&range=03-04

  Stats: 16 lines in 3 files changed: 4 ins; 11 del; 1 mod
  Patch: https://git.openjdk.org/jmh/pull/109.diff
  Fetch: git fetch https://git.openjdk.org/jmh.git pull/109/head:pull/109

PR: https://git.openjdk.org/jmh/pull/109