RFR: JDK-8297164: Update troff man pages and CheckManPageOptions.java

[Jonathan Gibbons]

Please review an update for the troff man pages, following the recent update to upgrade to use pandoc 2.19.2
(See https://bugs.openjdk.org/browse/JDK-8297165)

In conjunction with this, one javadoc test also needs to be updated, to work with the new form of output generated by the new version of pandoc.

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

Commit messages:
 - JDK-8297164: Update troff man pages and CheckManPageOptions.java

Changes: https://git.openjdk.org/jdk/pull/11223/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11223&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8297164
  Stats: 8944 lines in 29 files changed: 471 ins; 1589 del; 6884 mod
  Patch: https://git.openjdk.org/jdk/pull/11223.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11223/head:pull/11223

PR: https://git.openjdk.org/jdk/pull/11223