This PR proposes removing the entire internal `BufferStack` and associated classes and tests. Instead, we can now simply rely on a `Arena.ofConfined` which will provide pooling for us automatically.
If integrated, this PR would imply: 1,511 lines removed net across 13 files compared with master: - 602 production-source lines - 909 test and benchmark lines --------- - [x] I confirm that I make this contribution in accordance with the [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai). ------------- Commit messages: - Remove redundant classes and tests Changes: https://git.openjdk.org/jdk/pull/32924/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=32924&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8392541 Stats: 1522 lines in 13 files changed: 1 ins; 1512 del; 9 mod Patch: https://git.openjdk.org/jdk/pull/32924.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/32924/head:pull/32924 PR: https://git.openjdk.org/jdk/pull/32924
