RFR: 8352418: Add verification code to check that the associated loop nodes of useless Template Assertion Predicates are dead

[Christian Hagedorn]

As already suggested in https://github.com/openjdk/jdk/pull/23823, I want to do the following additional verification:

After `eliminate_useless_predicates()` all now useless `OpaqueTemplateAssertionPredicate` nodes should not have any references to `CountedLoop` nodes that are still in the graph (otherwise, they would have been marked useful). This verification did not work reliably without the full Assertion Predicates fix [JDK-8350577](https://bugs.openjdk.org/browse/JDK-8350577). Since JDK-8350577 is now integrated, I propose to add this additional verification code.

Thanks,
Christian

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Commit messages:
 - 8352418: Add verification code to check that the associated loop nodes of useless Template Assertion Predicates are dead

Changes: https://git.openjdk.org/jdk/pull/24326/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24326&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8352418
  Stats: 42 lines in 2 files changed: 42 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/24326.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24326/head:pull/24326

PR: https://git.openjdk.org/jdk/pull/24326