RFR: 8354196: C2: reorder and capitalize phase definition [v2]

[Christian Hagedorn]

On Thu, 12 Jun 2025 12:20:15 GMT, Manuel Hässig <mhaessig 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
>
> Manuel Hässig has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Split-If is a proper name

Marked as reviewed by chagedorn (Reviewer).

-------------

PR Review: https://git.openjdk.org/jdk/pull/25778#pullrequestreview-2921022602