Function widening_square_fixed 

pub const fn widening_square_fixed<const LIMBS: usize>(
    uint: &UintRef,
) -> (Uint<LIMBS>, Uint<LIMBS>)

Compute a wide squaring result for a fixed-size argument. Common power-of-two limb counts are implemented explicitly and used as a basis for general squaring.

The limb count of uint must be LIMBS.