[jdk18u] RFR: 8283890: Changes in CFG file format break C1Visualizer

[Tobias Hartmann]

Backport of [JDK-8283890](https://bugs.openjdk.java.net/browse/JDK-8283890). Applies cleanly. Approval is pending.

Thanks,
Tobias

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Commit messages:
 - 8283890: Changes in CFG file format break C1Visualizer

Changes: https://git.openjdk.org/jdk18u/pull/171/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk18u&pr=171&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8283890
  Stats: 4 lines in 1 file changed: 1 ins; 3 del; 0 mod
  Patch: https://git.openjdk.org/jdk18u/pull/171.diff
  Fetch: git fetch https://git.openjdk.org/jdk18u pull/171/head:pull/171

PR: https://git.openjdk.org/jdk18u/pull/171