RFR: 8282480: IGV: Use description instead of enum name for phases

[Christian Hagedorn]

[JDK-8281505](https://bugs.openjdk.java.net/browse/JDK-8281505) changed the `PrintIdeal` output to use the enum name of a phase when used with `PrintIdealPhase` instead of the description. However, it also changed the phase name shown in the IGV to the enum name. This should be reverted back for a better readability.

IGV after JDK-8281505:
![Screenshot from 2022-03-01 13-59-15](https://user-images.githubusercontent.com/17833009/156173248-7f6450cb-9816-437a-b5fa-816a2e214ad9.png)

IGV before JDK-8281505/with this patch:
![Screenshot from 2022-03-01 13-58-36](https://user-images.githubusercontent.com/17833009/156173243-0a0f975a-a44d-46a6-a48a-5183ff7600e1.png)

Thanks,
Christian

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Commit messages:
 - 8282480: IGV: Use description instead of enum name for phases

Changes: https://git.openjdk.java.net/jdk/pull/7645/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7645&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8282480
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7645.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7645/head:pull/7645

PR: https://git.openjdk.java.net/jdk/pull/7645