RFR: 8357621: G1: Clean up G1BiasedArray

[Thomas Schatzl]

Hi all,

  please review this minor touch-up of the G1BiasedArray classes, removing some unused methods and improving method visibility a bit.

Testing: gha

Thanks,
  Thomas

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Commit messages:
 - * remove whitespace
 - * one more method removed
 - 8357621

Changes: https://git.openjdk.org/jdk/pull/25406/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25406&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8357621
  Stats: 65 lines in 2 files changed: 19 ins; 46 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/25406.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25406/head:pull/25406

PR: https://git.openjdk.org/jdk/pull/25406