Function save_as_intervals

pub fn save_as_intervals<'tcx, N, R>(
    elements: &DenseLocationMap,
    body: &Body<'tcx>,
    results: R,
) -> SparseIntervalMatrix<N, PointIndex>
where
    N: Idx,
    R: ResultsVisitable<'tcx, Domain = BitSet<N>>,

Add points depending on the result of the given dataflow analysis.