RFR: 8375455: G1: Remove unused G1HeapRegionStats::coarsen_stats()

[Thomas Schatzl]

Hi all,

  please review this trivial removal of an unused method.

Testing: local compilation

Thanks,
  Thomas

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Commit messages:
 - 8375455

Changes: https://git.openjdk.org/jdk/pull/29253/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=29253&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8375455
  Stats: 9 lines in 2 files changed: 0 ins; 7 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/29253.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29253/head:pull/29253

PR: https://git.openjdk.org/jdk/pull/29253