RFR: 8372162: G1: Merging subclasses of G1IHOPControl into parent class

Wed Nov 19 15:21:33 UTC 2025

Merging two subclasses into the parent class to simplify type hierarchy. The internal `bool` flag doesn't introduce much complexity; instead, improves readability, IMO.

Perf neutral on linux-x64/aarch64: cachestree, dacapo, dacapo23, specjbb2005, specjbb2015, specjvm2008.

Test: tier1-5

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Commit messages:
 - g1-ihop

Changes: https://git.openjdk.org/jdk/pull/28391/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=28391&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8372162
  Stats: 321 lines in 5 files changed: 91 ins; 154 del; 76 mod
  Patch: https://git.openjdk.org/jdk/pull/28391.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28391/head:pull/28391

PR: https://git.openjdk.org/jdk/pull/28391