[jdk22] RFR: 8322235: Split up and improve LocaleProvidersRun

[Iris Clark]

On Fri, 12 Jan 2024 18:25:25 GMT, Justin Lu <jlu at openjdk.org> wrote:

> Please review this PR which is a backport of commit [4ea7b364](https://github.com/openjdk/jdk/commit/4ea7b36447ea96d62b1ca164c34e2b2b74a16579) from the [openjdk/jdk](https://git.openjdk.org/jdk) repository.
> 
> The original commit was a test-only change which optimized and split up the LocaleProvidersRun.java test.

Confirmed identical to changes in main-line.

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Marked as reviewed by iris (Reviewer).

PR Review: https://git.openjdk.org/jdk22/pull/68#pullrequestreview-1818908921