RFR: 8342988: GHA: Build JTReg in single step [v2]

[Aleksey Shipilev]

On Mon, 28 Oct 2024 13:36:54 GMT, Magnus Ihse Bursie <ihse at openjdk.org> wrote:

>> Aleksey Shipilev has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Rework for artifacts
>
> .github/actions/get-jtreg/action.yml line 59:
> 
>> 57:     - name: 'Build JTReg'
>> 58:       run: |
>> 59:         # If runner architecture is x64 set JAVA_HOME_17_X64 otherwise set to JAVA_HOME_17_arm64
> 
> This logic seems missing in your new script? Is it not needed? The new script seems to have X64 hardcoded; it looks wrong compared to this.

Intentional simplification: since we no longer build JTReg on actual various platforms, we can rely on current `ubuntu-22.04` runner that executes `prepare` job to be Linux x86_64. This also dodges the transient headache with building JTreg on different (broken) MSYS envs on Windows, if you remember that mess.

> .github/workflows/main.yml line 80:
> 
>> 78:         with:
>> 79:           sparse-checkout: |
>> 80:             .github
> 
> I'm guessing this does not add much extra time?

Yup! This checks out _only these files_, not the whole JDK workspace. Seems to run in < 1s. This would also resolve a TODO to move the rest of `prepare` job to scripts: it was apparently inlined _because_ we did not want to check out the entire JDK repo.

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PR Review Comment: https://git.openjdk.org/jdk/pull/21692#discussion_r1819110182
PR Review Comment: https://git.openjdk.org/jdk/pull/21692#discussion_r1819107442