Macro cipher::stream_cipher_bench

macro_rules! stream_cipher_bench {
    (
        $cipher:ty;
        $($name:ident $bs:expr;)*
    ) => { ... };
    (
        Key: $cipher:ty;
        $($name:ident $bs:expr;)*
    ) => { ... };
    (
        Init: $init:expr;
        $($name:ident $bs:expr;)*
    ) => { ... };
}

This is supported on crate feature dev only.

Create stream cipher benchmarks