_mod_SxS_ sometimes behaves as _aplmod_SxS_

Modulo is supposed to be equal to the c modulo in that -1 % 3 = -1.

When running the below program, 2 is printed instead, as if _aplmod_SxS_ were called.

int main ()
{
    StdIO::print (_mod_SxS_( _neg_S_(1), 3));
    return 0;
}

Output of sac2c -V:

sac2c 1.3.3-MijasCosta-1047-g0c4a5
build-type: RELEASE
built-by: "mverloop" at 2023-02-06T10:27:54