def_flags = SYMBOL_DEF << def;
for_all_symbols(i, sym) {
sym->flags |= SYMBOL_CHANGED;
sym->flags &= ~(def_flags|SYMBOL_VALID);
def_flags = SYMBOL_DEF << def;
for_all_symbols(i, sym) {
sym->flags |= SYMBOL_CHANGED;
sym->flags &= ~(def_flags|SYMBOL_VALID);