message: demo: Add a roundtrip test for exp encoding
  The error bound is larger than might be expected with 15 bits of
  mantissa due to a shared exponent.
diff: @@ -746,6 +746,13 @@ void encodeFilterExp()
  meshopt_encodeFilterExp(encoded, 1, 12, 15, data);
  assert(memcmp(encoded, expected, sizeof(expected)) == 0);
  +
  + float decoded[3];
  + memcpy(decoded, encoded, sizeof(decoded));
  + meshopt_decodeFilterExp(decoded, 3, 4);
  +
  + for (size_t i = 0; i < 3; ++i)
  + assert(fabsf(decoded[i] - data[i]) < 1e-3f);
  }
  static void clusterBoundsDegenerate()
  