RFR: 8364954: Migrate CleaningThread in BufferCleaner to InnocuousThread

[Roger Riggs]

On Wed, 6 Aug 2025 23:17:27 GMT, Liam Miller-Cushon <cushon at openjdk.org> wrote:

> This migrates a `Thread` introduced in [JDK-8344332](https://bugs.openjdk.org/browse/JDK-8344332) to use `InnocuousThread`, similar to the changes in [JDK-8345432](https://bugs.openjdk.org/browse/JDK-8345432) to migrate other uses of `Thread` in `java.nio` to `InnocuousThread`.

Looks good.

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

Marked as reviewed by rriggs (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/26665#pullrequestreview-3097344154