RFR: 8371643: Remove ThreadLocalAllocBuffer::_reserve_for_allocation_prefetch [v3]

[Albert Mingkun Yang]

> Trivial removing obsoleted code for unsupported arch.
> 
> Test: tier1

Albert Mingkun Yang has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:

 - Merge branch 'master' into remove-tlab-reserve
 - review
 - remove-tlab-reserve

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/28240/files
  - new: https://git.openjdk.org/jdk/pull/28240/files/0e447848..d6c34da7

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=28240&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=28240&range=01-02

  Stats: 10141 lines in 159 files changed: 5771 ins; 3554 del; 816 mod
  Patch: https://git.openjdk.org/jdk/pull/28240.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28240/head:pull/28240

PR: https://git.openjdk.org/jdk/pull/28240