RFR: JDK-8319139: Improve diagnosability of `JavadocTester` output

[Hannes Wallnöfer]

On Tue, 31 Oct 2023 20:13:22 GMT, Jonathan Gibbons <jjg at openjdk.org> wrote:

> Please review a small update to the output generated by `JavadocTester` when a test fails.
> 
> Although `JavadocTester` does report a stack trace, it appears after all the content of the failure message, which may be some distance away if the message is long.
> 
> The `String message` parameter for `passed` and `failed` is split in two: `String message, String... details` with the intent that the `message` should be a short one-line message, and any long additional info put in the effectively optional `details`.
> 
> The stack trace is now generated immediately after the initial `FAILED: `_message_ line and before the `details`.
> Using a varargs `details` means that we do not have to concatenate strings with `\n`.
> 
> There are some other minor tweaks to the output to make it slightly less cryptic.
> 
> `JavadocTester` does have some specific tests of its own, and these are updated as appropriate.

Looks good to me. Looking forward for seeing the new message format "in the wild".

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Marked as reviewed by hannesw (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/16436#pullrequestreview-1707948050