Method reverse_index

cranelift/codegen/src/ranges.rs:82–90

Reverse this list of ranges, so that the first range is at the last index and the last range is at the first index. ```ignore use cranelift_codegen::ranges::Ranges; let mut ranges = Ranges::default(); ranges.push_end(4); ranges.push_end(6); ranges.reverse_index(); assert_eq!(ranges.get(0), 4..6); assert_eq!(ranges.get(1), 0..4); ```

(&mut self)

    /// assert_eq!(ranges.get(1), 0..4);
    /// ```
    pub fn reverse_index(&mut self) {
        // We can't easily change the order of the endpoints in
        // self.ranges: they need to be in ascending order or our
        // compressed representation gets complicated. So instead we
        // change our interpretation of indexes using map_index below,
        // controlled by a simple flag. As a bonus, reversing the list
        // is constant-time!
        self.reverse = !self.reverse;
    }

    fn map_index(&self, index: usize) -> usize {
        if self.reverse {