RFR: 8346781: [JVMCI] Limit ServiceLoader to class initializers [v2]

[Doug Simon]

On Mon, 17 Feb 2025 16:12:41 GMT, Doug Simon <dnsimon at openjdk.org> wrote:

>> In the context of libgraal, the current use of ServiceLoader in JVMCI is problematic as libgraal does all class loading at image build time. There are static fields such as `JVMCIServiceLocator.cachedLocators` that need to be initialized [via reflection](https://github.com/oracle/graal/blob/30492c3f7847a13ae7f8dc50663a5a039e49a8e7/compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/hotspot/libgraal/BuildTime.java#L175-L180) when building libgraal.
>> 
>> This PR removes the need for such reflection by moving all use of ServiceLoader in JVMCI into `<clinit>` methods. These methods are executed when building libgraal. It also removes a few other public methods and fields that are no longer used by Graal. Given that JVMCI is still experimental and only has qualified exports to Graal, I don't think this needs a CSR.
>
> Doug Simon has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:
> 
>  - Merge remote-tracking branch 'openjdk-jdk/master' into JDK-8346781
>  - remove non-native-image build time use of ServiceLoader
>  - make Cleaner.clean public

Passes openjdk-pr-canary: https://github.com/dougxc/openjdk-pr-canary/actions/runs/13374826011/job/37351770830#step:4:47

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PR Comment: https://git.openjdk.org/jdk/pull/22869#issuecomment-2663687923