RFR: 8348301: Remove unused Reference.waitForReferenceProcessing break-ins in tests

[Alan Bateman]

On Wed, 22 Jan 2025 16:59:04 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> `Reference.waitForReferenceProcessing` is in internal API, which should go away with [JDK-8344332](https://bugs.openjdk.org/browse/JDK-8344332). There is single use of that internal API in the tests, the last use of which was removed by [JDK-8080225](https://bugs.openjdk.org/browse/JDK-8080225). We can remove the `Reference.waitForReferenceProcessing` break-ins in the tests now.
> 
> Additional testing:
>  - [x] Affected test still passes

So the test wasn't actually calling Reference::waitForReferenceProcessing, do I have this right? In that case, this PR looks fine.

-------------

Marked as reviewed by alanb (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/23239#pullrequestreview-2569532000