[lworld] RFR: 8331551: [lworld] compiler/gcbarriers/TestZGCUnrolling.java fails after merging jdk-23+6

[Damon Fenacci]

Re-activating the IR check removed in [JDK-8331538](https://bugs.openjdk.org/browse/JDK-8331538) as `compiler/gcbarriers/TestZGCUnrolling.java` is not failing anymore.

Testing: Tier1-3

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Commit messages:
 - JDK-8331551: [lworld] compiler/gcbarriers/TestZGCUnrolling.java fails after merging jdk-23+6

Changes: https://git.openjdk.org/valhalla/pull/1488/files
  Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=1488&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8331551
  Stats: 2 lines in 1 file changed: 0 ins; 1 del; 1 mod
  Patch: https://git.openjdk.org/valhalla/pull/1488.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1488/head:pull/1488

PR: https://git.openjdk.org/valhalla/pull/1488