parse_error: add comment explaining clang's -Wweak-vtables warning
parse_error: add comment explaining clang's -Wweak-vtables warning

thomastrapp/hext,thomastrapp/hext,thomastrapp/hext,thomastrapp/hext,thomastrapp/hext,thomastrapp/hext,thomastrapp/hext,thomastrapp/hext