message: Validate that functions don't return more than 1 value
diff: @@ -97,6 +97,10 @@ inline parser_result<FuncType> parse(const uint8_t* pos, const uint8_t* end)
  FuncType result;
  std::tie(result.inputs, pos) = parse_vec<ValType>(pos, end);
  std::tie(result.outputs, pos) = parse_vec<ValType>(pos, end);
  +
  + if (result.outputs.size() > 1)
  + throw validation_error{"function has more than one result"};
  +
  return {result, pos};
  }
  