[Bug middle-end/104966] [11/12 Regression] Yet another bogus -Warray-bounds warning in libstdc++ headers

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104966

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Well, the IL definitely has

 tem = operator new[] (0);
 /* some magic computing with 'positive_sign_size' */
 if (min (positive-sign-size, something) != 0)
   if (__n == 1)
     ;
   else
     {
       tem = __n * 4;
       if (tem != 0)
         __builtin_memmove (dest, ..., tem);

so I guess that "magic" should always evaluate to 0 but we are not able
to figure that out despite the allocation being statically size zero.
You might be able to pin-point the libstdc++ piece with that magic?