We know it already, but with current loading code VM will hash it once
more. It doesn't help a lot and still it costs nothing to avoid this
overhead.
name old time/op new time/op delta
VerifyWitness-8 93.4µs ± 3% 92.7µs ± 2% ~ (p=0.353 n=10+10)
name old alloc/op new alloc/op delta
VerifyWitness-8 3.43kB ± 0% 3.40kB ± 0% -0.70% (p=0.000 n=9+9)
name old allocs/op new allocs/op delta
VerifyWitness-8 67.0 ± 0% 66.0 ± 0% -1.49% (p=0.000 n=10+10)
