RFR: 8182774: Verify code in javap

[Adam Sotona]

This patch adds `javap -verify` option to check the class and print obvious verification errors found.
Implementation depends on extended Class-File API verification support, so PR #16809 is important to precede.
The new `javap` option is mentioned in man pages and a release note will be provided.

Please review.

Thank you,
Adam

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Depends on: https://git.openjdk.org/jdk/pull/16809

Commit messages:
 - added VerificationTest
 - Merge branch 'JDK-8320396-verifier-extension' into JDK-8182774-javap-verify
 - added description to javap cmd help and man page
 - 8182774: Verify code in javap

Changes: https://git.openjdk.org/jdk/pull/18629/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18629&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8182774
  Stats: 101 lines in 6 files changed: 101 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/18629.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18629/head:pull/18629

PR: https://git.openjdk.org/jdk/pull/18629