WLPROP bug

When compiling this (originally issue 2467):

inline double +(double a, double b) { return _add_SxS_(a, b); }
inline double *(double a, double b) { return _mul_SxS_(a, b); }

double sum(double[d:shp] x)
{
  return with {
          (_mul_SxV_(0, shp) <= iv < shp): _sel_VxA_(iv, x);
         }: fold(+, 0d);
}

struct Particle {
  double x;
  double angle;
  double y;
};

inline
struct Particle[n]
step_particles(struct Particle[n] particles)
{
  particles.x = {iv -> _sel_VxA_(iv, particles.x) * _sel_VxA_(iv, particles.angle)};
  particles.y = {iv -> _sel_VxA_(iv, particles.y) + _sel_VxA_(iv, particles.angle)};

        return particles;
}

int main() {
        particle_count  = 20;

        particles = {iv -> Particle {.x     = 4d,
                               .y     = 100d,
                               .angle = 1.0}
                   | iv < [particle_count]};

  for (i = 0; _lt_SxS_(i, 10); i = _add_SxS_(i, 1)) {
          particles = step_particles(particles);
  }

        return _toi_S_(sum(particles.x));
}

with sac2c 2.0.0-Tintigny-95-gde1f7 and -bopt the loop function contains this WL:

 _pinl_1169__flat_110 = with      /** FOLDABLE (all gen's const) **/
      /** REFERENCED: 2 (total num refs) **/
 {
        /* Partn */
        ([ 0 ] <= _pinl_1201_iv=[_pinl_1221__eat_524] (IDXS:_wlidx_3239__pinl_1169__flat_110) < [ 20 ] genwidth [ 20 ])
        {
          _ivesli_3255 = _idxs2offset_( [ 20 ], _pinl_1221__eat_524);
          _pinl_1174__flat_217 = _idx_sel_( _ivesli_3255, _dss_977_particles_x) /* no constant offset in dim 1 */;
          _pinl_1236__flat_28 = _mul_SxS_( _pinl_1174__flat_217, 4.0);
        } : _pinl_1236__flat_28 ;
         } :
      /* RC (_dss_977_particles_x) */
      genarray( [ 20 ], _pinl_1171__flat_145, IDX(_wlidx_3239__pinl_1169__flat_110));

The error lies in the second argument of _mul_SxS_: this should be 1.0 (angle) instead of 4.0 (x).