RFR: 8355915: [leyden] Crash in MDO clearing the unloaded array type

[Vladimir Ivanov]

On Tue, 29 Apr 2025 14:57:23 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> Caught this when doing benchmarks with Spring Boot. See the bug for reproducer.
> 
> The lifecycle of array types of `T` is bound to the lifecycle of `T` themselves. So the fix does similar thing to `is_excluded` and other code: when we encounter the `T[]`, we ask if its bottom component classes is not yet initialized. This fits nicely with our current uses, which skip such classes, and ever touch their (potentially nullptr) CLDs.
> 
> Additional testing:
>  - [x] Ad-hoc testing with most recent spring-boot-petclinic
>  - [x] Linux x86_64 server fastdebug, `runtime/cds`

Looks good.

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Marked as reviewed by vlivanov (Committer).

PR Review: https://git.openjdk.org/leyden/pull/64#pullrequestreview-2804680274