message: Fix RefOrTagged::get_as_int()
  Revert back to original implementation. It was probably modyfied by
  a mistake.
diff: @@ -1035,7 +1035,8 @@ inline ref_type RefOrTagged::get_as_ref() const noexcept
  inline uint_fast64_t RefOrTagged::get_as_int() const noexcept
  {
  - return (m_value >> 1);
  + // The bitwise AND is there in case uint_fast64_t is wider than 64 bits.
  + return (uint_fast64_t(m_value) & 0xFFFFFFFFFFFFFFFFULL) >> 1;
  }
  inline RefOrTagged RefOrTagged::make_ref(ref_type ref) noexcept
  