hg: code-tools/jmh: Amend "7902560: Race in indent generation code" with test

[shade at redhat.com]

Changeset: c434f013bc2e
Author:    shade
Date:      2020-01-03 16:36 +0100
URL:       https://hg.openjdk.java.net/code-tools/jmh/rev/c434f013bc2e

Amend "7902560: Race in indent generation code" with test

+ jmh-core/src/test/java/org/openjdk/jmh/generators/core/BenchmarkGeneratorTest.java