8058610: must not let long operations overflow
Reviewed-by: hannesw, jlaskey, lagergren
=== mul ===
4611686014132420600
36893488130239234000
=== self_mul ===
4611686014132420600
36893488130239234000
=== sub ===
4294967294
18446744073709552000
=== self_sub ===
4294967294
18446744073709552000
=== add ===
4294967294
18446744073709552000
=== self_add ===
4294967294
18446744073709552000