RFR: 8328364: Remove redundant fields in 'BOTConstants'

[Guoxiong Li]

Hi all,

The class `BOTConstants` has several redundant fields. This patch removes the redundant fields and adds a new field `CardTable::_card_shift_in_words` like `BOTConstants::_log_card_size_in_words`.

Thanks for taking the time to review.

Best Regards,
-- Guoxiong

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Commit messages:
 - Remove redundant fields.

Changes: https://git.openjdk.org/jdk/pull/18371/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18371&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8328364
  Stats: 136 lines in 16 files changed: 10 ins; 64 del; 62 mod
  Patch: https://git.openjdk.org/jdk/pull/18371.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18371/head:pull/18371

PR: https://git.openjdk.org/jdk/pull/18371