RFR: 8349835: C2: simplify IGV property printing [v3]

[Roberto Castañeda Lozano]

On Mon, 27 Oct 2025 22:03:44 GMT, Saranya Natarajan <snatarajan at openjdk.org> wrote:

>> The code that prints node properties and live range properties is very verbose and repetitive and could be simplified by applying a refactoring suggested [here](https://github.com/openjdk/jdk/pull/23558#discussion_r1950785708).
>> 
>> ### Fix 
>> Implemented the suggested refactoring. 
>> 
>> ### Testing 
>> Github Actions, Tier 1-3
>
> Saranya Natarajan has updated the pull request incrementally with one additional commit since the last revision:
> 
>   addressing review comments#2

Thanks for working on this, Saranya! We do not have good test coverage of IGV graph dumping, so only running regular tier testing might not catch possible regressions introduced by this changeset. Consider also comparing the XML graphs dumped before and after the changeset for a few well-known methods with deterministic compilation, e.g.:

$ ${BASELINE_JAVA} -Xbatch -XX:PrintIdealGraphLevel=6 -XX:CompileOnly=java.lang.String::charAt -XX:PrintIdealGraphFile=before.xml
$ ${PATCHED_JAVA}  -Xbatch -XX:PrintIdealGraphLevel=6 -XX:CompileOnly=java.lang.String::charAt -XX:PrintIdealGraphFile=after.xml
$ diff before.xml after.xml

The only expected changes between the two files would be things like memory addresses, process and thread IDs, etc. But all the other properties should remain the same.

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PR Review: https://git.openjdk.org/jdk/pull/26902#pullrequestreview-3387223174