This REDO PR has two commits. The first commit is a straight re-application of the original [JDK-8371643](https://bugs.openjdk.org/browse/JDK-8371643) change that removes `ThreadLocalAllocBuffer::_reserve_for_allocation_prefetch` and related code.
That original change was backed out after it surfaced two pre-existing issues: a real bug on master ([JDK-8373021](https://bugs.openjdk.org/browse/JDK-8373021), now fixed), and an intermittent test bug in `compiler/unsafe/AlignmentGapAccess.java` ([JDK-8373487](https://bugs.openjdk.org/browse/JDK-8373487)). The second commit temporarily adds `compiler/unsafe/AlignmentGapAccess.java` to the ProblemList. The reason is that this TLAB cleanup makes that intermittent failure happen much more frequently. Of course we can wait until that test bug is fixed, but I think it is better to merge this sooner and keep that test in the ProblemList for now. That lets us keep incubating this cleanup in CI while also giving us a better chance to uncover other existing issues. Test: tier1-3 ------------- Commit messages: - problemlist - tlab-redo Changes: https://git.openjdk.org/jdk/pull/30214/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=30214&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8373369 Stats: 72 lines in 8 files changed: 2 ins; 67 del; 3 mod Patch: https://git.openjdk.org/jdk/pull/30214.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/30214/head:pull/30214 PR: https://git.openjdk.org/jdk/pull/30214
