message: quench a GCC warning about ek::empty
diff: @@ -784,6 +784,11 @@ template <typename T> ENOKI_INLINE T zero(size_t size) {
  }
  }
  +# if defined(__GNUC__) && !defined(__clang__)
  +# pragma GCC diagnostic push
  +# pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
  +# endif
  +
  template <typename T> ENOKI_INLINE T empty(size_t size = 1) {
  ENOKI_MARK_USED(size);
  if constexpr (is_array_v<T>) {
  @@ -804,6 +809,10 @@ template <typename T> ENOKI_INLINE T empty(size_t size = 1) {
  }
  }
  +# if defined(__GNUC__) && !defined(__clang__)
  +# pragma GCC diagnostic pop
  +# endif
  +
  template <typename T, typename T2>
  ENOKI_INLINE T full(const T2 &value, size_t size = 1) {
  ENOKI_MARK_USED(size);
  