RFR: 8354196: C2: reorder and capitalize phase definition

[Manuel Hässig]

On Thu, 12 Jun 2025 11:37:20 GMT, Christian Hagedorn <chagedorn at openjdk.org> wrote:

>> This PR performs some cleanup and formatting around the phase definitions in C2:
>>  - the phase descriptions are capitalized according to the [MLA Handbook title case rules](https://en.wikipedia.org/wiki/Title_case#Modern_Language_Association_(MLA)_Handbook),
>>  - the phases are reordered to be more or less in the order of execution or occurrence in the code,
>>  - the definitions in `phasetype.hpp` and `CompilePhase.java` are synced,
>>  - `CompilePhase.java` is aligned for better readability.
>> 
>> This change was tested on:
>>  - [x] [Github Actions](https://github.com/mhaessig/jdk/actions/runs/15605662671)
>>  - [x] tier1 plus some Oracle internal testing
>
> src/hotspot/share/opto/phasetype.hpp line 54:
> 
>> 52:   flags(PHASEIDEAL_BEFORE_EA,           "PhaseIdealLoop before EA") \
>> 53:   flags(AFTER_EA,                       "After Escape Analysis") \
>> 54:   flags(ITER_GVN_AFTER_EA,              "Iter GVN after EA") \
> 
> Not sure if this should be also part of this change but we might want to consider "Iter GVN" -> IGVN (same for left hand sides of `flags()`.

I will comment on JDK-8319599 to propose it.

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PR Review Comment: https://git.openjdk.org/jdk/pull/25778#discussion_r2142552139