RFR: 8366829: Add constants for the Duration MIN/MAX values

[Roger Riggs]

On Fri, 26 Sep 2025 23:06:36 GMT, Pavel Rappo <prappo at openjdk.org> wrote:

> We have [recently discussed][] a possibility of adding the `Duration.MIN` and `Duration.MAX` constants. Can we now start implementation? If and when we are in agreement on this PR, I will file a CSR.
> 
> I drafted a minimal specification and added some tests. I tried to phrase the spec for `Duration.MIN` in a way that makes it clear that `Duration.MIN` is the most negative value and not the least positive.
> 
> [recently discussed]: https://mail.openjdk.org/pipermail/core-libs-dev/2025-September/151098.html

Looks good, better with copyright updates.

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PR Review: https://git.openjdk.org/jdk/pull/27534#pullrequestreview-3280653998