RFR: 8255245: C1: Fix output of -XX:+PrintCFGToFile to open it with visualizer

[Christian Hagedorn]

[JDK-8251093](https://bugs.openjdk.java.net/browse/JDK-8251093) introduced some improved logging for intervals. When specifying `-XX:+PrintCFGToFile` to dump the graph to a file to later open it with the C1 visualizer, it also uses the improved interval printing. However, this output can no longer be read by the C1 Visualizer. As the C1 Visualizer is not part of the JDK, we should include the old format again for the output produced by `-XX:+PrintCFGToFile` to be compatible with the visualizer again. The console output can still use the improved logging of JDK-8251093.

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Commit messages:
 - 8255245: C1: Fix output of -XX:+PrintCFGToFile to open it with visualizer

Changes: https://git.openjdk.java.net/jdk/pull/837/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=837&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8255245
  Stats: 38 lines in 3 files changed: 26 ins; 2 del; 10 mod
  Patch: https://git.openjdk.java.net/jdk/pull/837.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/837/head:pull/837

PR: https://git.openjdk.java.net/jdk/pull/837