[Bug target/125451] [16/17 Regression] wcwidth broken with gcc 16 on cygwin

[towo at computer dot org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125451

--- Comment #12 from Thomas Wolff <towo at computer dot org> ---
In cygwin, it's 
typedef unsigned short wchar_t;
(for interworking with Windows)
and
int wcwidth(const wint_t wc);

but an unsigned short must not be sign-extended into an int.