RFR: 8327361: Update some comments after JDK-8139457

[Roman Kennke]

A follow-up to [8139457: Relax alignment of array elements](https://bugs.openjdk.org/browse/JDK-8139457) ([PR](https://git.openjdk.org/jdk/pull/11044)), some comments need an update.

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Commit messages:
 - 8327361: Update some comments after JDK-8139457

Changes: https://git.openjdk.org/jdk/pull/18120/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18120&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8327361
  Stats: 12 lines in 2 files changed: 0 ins; 0 del; 12 mod
  Patch: https://git.openjdk.org/jdk/pull/18120.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18120/head:pull/18120

PR: https://git.openjdk.org/jdk/pull/18120