RFR: Merge jdk18

Fri Dec 10 18:13:18 UTC 2021

Forwardport JDK 18 -> JDK 19

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Commit messages:
 - Merge
 - 8277621: ARM32: multiple fastdebug failures with "bad AD file" after JDK-8276162
 - 8278538: Test langtools/jdk/javadoc/tool/CheckManPageOptions.java fails after the manpage was updated
 - 8273179: Update nroff pages in JDK 18 before RC

The merge commit only contains trivial merges, so no merge-specific webrevs have been generated.

Changes: https://git.openjdk.java.net/jdk/pull/6802/files
  Stats: 1142 lines in 30 files changed: 688 ins; 155 del; 299 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6802.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6802/head:pull/6802

PR: https://git.openjdk.java.net/jdk/pull/6802