Tracking Issue for `align_to_uninit_mut`

This is a tracking issue for safe variant of slice::align_to_mut for MaybeUninit values.

// core::slice

impl<T> [MaybeUninit<T>] {
    pub fn align_to_uninit_mut<U>(&mut self) -> (&mut Self, &mut [MaybeUninit<U>], &mut Self);
}