{"ast_node_type":"function","tokens":[{"end":96,"kind":"keyword","start":0,"text":"fn"}]}
    fn new(arms: &[MatchArm<'p, Cx>], scrut_ty: Cx::Ty, scrut_validity: PlaceValidity) -> Self {
    /// Build a new matrix from an iterator of `MatchArm`s.
        let place_info = PlaceInfo {