RFR: 8347554: [BACKOUT] C2: implement optimization for series of Add of unique value

[Christian Hagedorn]

The Java Fuzzer found a wrong execution which could be traced back to [JDK-8325495](https://bugs.openjdk.org/browse/JDK-8325495) which went into JDK 24. Since we are close to RDP 2, a backout seems the safest option for JDK 24. A REDO can be done for JDK 25 @tabjy.

Details about the wrong execution and how to trigger it can be found in the JBS description of this backout.

The backout applied cleanly.

Thanks,
Christian

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Commit messages:
 - Revert "8325495: C2: implement optimization for series of Add of unique value"

Changes: https://git.openjdk.org/jdk/pull/23066/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23066&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8347554
  Stats: 414 lines in 3 files changed: 0 ins; 414 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/23066.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23066/head:pull/23066

PR: https://git.openjdk.org/jdk/pull/23066