RFR: 8351462: Improve robustness of String concatenation [v2]

[Roger Riggs]

On Wed, 9 Apr 2025 13:32:00 GMT, Raffaello Giulietti <rgiulietti at openjdk.org> wrote:

>> Early detection of an `int` overflow in `StringConcatHelper` improves robustness of `StringConcatFactory`.
>
> Raffaello Giulietti has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Bumped copyright year.

Looks good

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Marked as reviewed by rriggs (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/24546#pullrequestreview-2753819343