symbol_id_get (symbol const *sym)
{
  if (sym->alias)
    sym = sym->alias;
  return is_identifier (sym->tag) ? sym->tag : 0;
}
symbol_id_get (symbol const *sym)
{
  if (sym->alias)
    sym = sym->alias;
  return is_identifier (sym->tag) ? sym->tag : 0;
}