{"ast_node_type":"other","tokens":[{"end":99,"kind":"keyword","start":0,"text":"//"}]}
        // We need to ensure at least 16 entries in our vector type, since the pre-reversed vectors
        let type_size_bytes = elem_size_bytes as u64 * in_len;
        // we generate below have 16 entries in them.  `new_rvalue_vector_perm` requires the mask