[Issue 18307] -transition=intpromote deprecation message confusing

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=18307

--- Comment #2 from Zach the Mystic <reachzach at gmail.com> ---
...or whatever negative Integral type it requires. (I did only test it with
`int`, but I think it should work regardless.

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