RFR: 8339631: Fix block @jls and @jvms tags

[Pavel Rappo]

This fixes some of the recently discovered [issues] with the block variants of the specification tags. While reviewing, please check the proposed changes against the actual specifications. Since the specifications for JDK 23 are not yet available in the HTML format, you can use the specifications for JDK 22, which are reasonably up-to-date:

  - [JLS]
  - [JVMS]

Note that this PR does NOT address any issues with the inline variants of the said tags. Those are harder to check. Even flagging suspicious tags requires a human. If you have some time, consider performing similar checks for inline `@jls` and `@jvms` tags in your area. Thanks.

[issues]: https://bugs.openjdk.org/browse/JDK-8339558
[JLS]: https://docs.oracle.com/javase/specs/jls/se22/html/index.html
[JVMS]: https://docs.oracle.com/javase/specs/jvms/se22/html/index.html

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Commit messages:
 - Initial commit

Changes: https://git.openjdk.org/jdk/pull/20879/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20879&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8339631
  Stats: 37 lines in 21 files changed: 0 ins; 0 del; 37 mod
  Patch: https://git.openjdk.org/jdk/pull/20879.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20879/head:pull/20879

PR: https://git.openjdk.org/jdk/pull/20879