RFR: 8323012: C2 fails with fatal error: no reachable node should have no use

[Tobias Hartmann]

Incorrect refactoring from [JDK-8322490](https://bugs.openjdk.org/browse/JDK-8322490), probably a copy-paste error, leads to a dead `CastPP` and might have other not yet observed effects. See JBS for details.

I wasn't able to extract a regression test for this but it reliably reproduced with replay compilation.

Thanks,
Tobias

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Commit messages:
 - 8323012: C2 fails with fatal error: no reachable node should have no use

Changes: https://git.openjdk.org/jdk/pull/17276/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17276&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8323012
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/17276.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17276/head:pull/17276

PR: https://git.openjdk.org/jdk/pull/17276