[jdk25] RFR: 8315131: Clarify VarHandle set/get access on 32-bit platforms

[Chen Liang]

JDK-8315131 addresses a doc-only mistake present on release 25. Since this is doc-only, this is eligible for backport, and its CSR is approved for release 25 too. See #26258 for the original PR review.

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Commit messages:
 - Backport ea6674fec8702eea481afa7ca7e522cbacd53841

Changes: https://git.openjdk.org/jdk/pull/26438/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=26438&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8315131
  Stats: 8 lines in 2 files changed: 1 ins; 0 del; 7 mod
  Patch: https://git.openjdk.org/jdk/pull/26438.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26438/head:pull/26438

PR: https://git.openjdk.org/jdk/pull/26438