RFR: 7903903: JMH: Tighten up generated code density [v2]

[Aleksey Shipilev]

> Part of [JDK-8345302](https://bugs.openjdk.org/browse/JDK-8345302), we want to generate denser scaffolding code. This is an umbrella task to tighten up the generated code without heavy restructuring.

Aleksey Shipilev has updated the pull request incrementally with one additional commit since the last revision:

  Touchups

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Changes:
  - all: https://git.openjdk.org/jmh/pull/142/files
  - new: https://git.openjdk.org/jmh/pull/142/files/be513425..125028da

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jmh&pr=142&range=01
 - incr: https://webrevs.openjdk.org/?repo=jmh&pr=142&range=00-01

  Stats: 42 lines in 2 files changed: 20 ins; 16 del; 6 mod
  Patch: https://git.openjdk.org/jmh/pull/142.diff
  Fetch: git fetch https://git.openjdk.org/jmh.git pull/142/head:pull/142

PR: https://git.openjdk.org/jmh/pull/142