RFR: 6607: Better descriptions for the code cache rule

[Suchita Chaturvedi]

This PR provides better description for code cache rule.

Before the change:
![image](https://github.com/user-attachments/assets/487bca61-ceee-4dda-bc70-9c99316d4ee7)

After the change:
<img width="398" alt="image" src="https://github.com/user-attachments/assets/45d1b16d-47ea-4e78-add0-21d682e5ccbe">

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Commit messages:
 - 6607: Better descriptions for the code cache rule

Changes: https://git.openjdk.org/jmc/pull/607/files
  Webrev: https://webrevs.openjdk.org/?repo=jmc&pr=607&range=00
  Issue: https://bugs.openjdk.org/browse/JMC-6607
  Stats: 14 lines in 2 files changed: 9 ins; 0 del; 5 mod
  Patch: https://git.openjdk.org/jmc/pull/607.diff
  Fetch: git fetch https://git.openjdk.org/jmc.git pull/607/head:pull/607

PR: https://git.openjdk.org/jmc/pull/607