Delegate trait impl assist: #[cfg] is not considered when enumerating impls

[pickx]

Following #14948, and using @Veykril's example

pub(crate) struct RibStack<R> {
    $0ribs: Vec<R>,
    used: usize,
}

choosing Delegate trait impl for field... and then Generate delegate impl clone::Clone for ribs will generate

impl<T: Clone, A: std::alloc::Allocator + Clone> Clone<T, A> for RibStack {
    fn clone(&self) -> Self {
        <Vec as Clone<T, A>>::clone( &self.ribs )
    }

    fn clone(&self) -> Self {
        <Vec as Clone<T, A>>::clone( &self.ribs )
    }

    fn clone_from(&mut self, other: &Self) {
        <Vec as Clone<T, A>>::clone_from( &mut self.ribs , other)
    }
}

note how clone(&self) is generated twice. I believe this is both this one and this one. It seems that although one is #[cfg(test)] and the other is #[cfg(not(test))], both are chosen.

I'm currently trying to look at how to solve this but I'm new and and would appreciate some guidance.