message: Optimize push() helper in parse_expr()
diff: @@ -15,8 +15,9 @@ inline void store(uint8_t* dst, T value) noexcept
  template <typename T>
  inline void push(bytes& b, T value)
  {
  - b.resize(b.size() + sizeof(value));
  - store(&b[b.size() - sizeof(value)], value);
  + uint8_t storage[sizeof(T)];
  + store(storage, value);
  + b.append(storage, sizeof(storage));
  }
  struct LabelPosition
  