RFR: 8337213: Shenandoah: Add verification for class mirrors

[Roman Kennke]

On Thu, 25 Jul 2024 14:35:37 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> When working in Leyden, I noticed some oddities when loading Class mirrors from the CDS archive. These are not caught by Shenandoah asserts or verifier, since the problem is due to wrong metadata. We can amend verification to test these. 
> 
> Additional testing:
>  - [x] Linux x86_64 server fastdebug, `all` with `-XX:+UseShenandoahGC`
>  - [x] Linux x86_64 server fastdebug, `all` with `-XX:+UseShenandoahGC -XX:+ShenandoahVerify`

Looks reasonable. Thanks!

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Marked as reviewed by rkennke (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/20332#pullrequestreview-2205195325