message: enoki::squared_norm(): use FMA
diff: @@ -613,7 +613,14 @@ ENOKI_INLINE auto abs_dot_async(const T1 &a1, const T2 &a2) {
  }
  template <typename T> ENOKI_INLINE auto squared_norm(const T &v) {
  + if constexpr (array_depth_v<T> == 1 || array_size_v<T> == 0) {
  return hsum(v * v);
  + } else {
  + value_t<T> result = sqr(v.x());
  + for (size_t i = 1; i < v.size(); ++i)
  + result = fmadd(v.entry(i), v.entry(i), result);
  + return result;
  + }
  }
  template <typename T> ENOKI_INLINE auto norm(const T &v) {
  