message: `sample_shifted`: fix taking reference to constexpr
diff: @@ -130,7 +130,7 @@ NAMESPACE_BEGIN(detail)
  template <typename Array, size_t... Index, typename Value = value_t<Array>>
  ENOKI_INLINE Array sample_shifted(Value sample, std::index_sequence<Index...>) {
  - const Array shift((Value(Index) / Value(Array::Size))...);
  + const Array shift(Index / scalar_t<Array>(Array::Size)...);
  Array value = Array(sample) + shift;
  value[value > Value(1)] -= Value(1);
  