Macro check_arch_independent_same_layout 

macro_rules! check_arch_independent_same_layout {
    {} => { ... };
    {
        $type_name1:ty = $type_name2:ident
        {
            $(
                $($field1:ident).+ => $($field2:ident).+
            ),*
            $(,)?
        }
        $($token:tt)*
    } => { ... };
}

Ensure a custom type has the same layout as an ABI independant uapi type

Usage:

check_arch_independent_same_layout! {
    Type = UapiType {
        type_field1 => uapi_type_field1,
        type_field2 => uapi_type_field2,
        ...
    }
}