RFR: 8373145: [BACKOUT] Remove ThreadLocalAllocBuffer::_reserve_for_allocation_prefetch

Fri Dec 5 16:18:01 UTC 2025

Clean revert of [JDK-8371643](https://bugs.openjdk.org/browse/JDK-8371643) to reduce CI noise.

`runtime/cds/appcds/methodHandles/MethodHandlesSpreadArgumentsTest.java` with `-XX:+UseZGC -XX:+UseCompactObjectHeaders` fails 10% of the time.

After the revert, the test passes 2K runs.

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Commit messages:
 - Revert "8371643: Remove ThreadLocalAllocBuffer::_reserve_for_allocation_prefetch"

Changes: https://git.openjdk.org/jdk/pull/28679/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=28679&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8373145
  Stats: 69 lines in 7 files changed: 66 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/28679.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28679/head:pull/28679

PR: https://git.openjdk.org/jdk/pull/28679