Macro bitflags_array

macro_rules! bitflags_array {
    (
        $(#[$outer:meta])*
        pub struct $name:ident: [$T:ty; $Len:expr];

        $(
            $(#[$bit_outer:meta])*
            $vis:vis struct $inner_name:ident $lower_inner_name:ident {
                $(
                    $(#[$inner:ident $($args:tt)*])*
                    const $Flag:tt = $value:expr;
                )*
            }
        )*
    ) => { ... };
}

Macro for creating sets of bitflags, we need this because there are almost more flags than bits in a u64, we can’t use a u128 because of FFI, and the number of flags is increasing.