RFR: 8333917: G1: Refactor G1CollectedHeap::register_old_region_with_region_attr

[Albert Mingkun Yang]

Trivial using literal when it's statically known.

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Commit messages:
 - trivial

Changes: https://git.openjdk.org/jdk/pull/19634/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19634&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8333917
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/19634.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19634/head:pull/19634

PR: https://git.openjdk.org/jdk/pull/19634