Function fiat_crypto::secp256k1_32::fiat_secp256k1_selectznz

pub fn fiat_secp256k1_selectznz(
    out1: &mut [u32; 8], 
    arg1: fiat_secp256k1_u1, 
    arg2: &[u32; 8], 
    arg3: &[u32; 8]
)