RFR: JDK-8316559: Refactor some util/Calendar tests to JUnit [v2]

[Naoto Sato]

On Fri, 22 Sep 2023 19:50:49 GMT, Justin Lu <jlu at openjdk.org> wrote:

>> Please review this PR which converts some tests under _Calendar_ to use JUnit. These tests either previously used the internal _IntlTest_, or used no framework at all. 
>> 
>> Any files named BugXXXXXXX.java will be renamed after review.
>
> Justin Lu has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - Review: revert removal of SupressWarnings annotation
>  - Reflect review comments

Marked as reviewed by naoto (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/15853#pullrequestreview-1640604118