{"ast_node_type":"variable","tokens":[{"end":99,"kind":"keyword","start":0,"text":"let"}]}
        let shift_idx = bx.cx.const_int(bx.type_ix(in_elem_bitwidth), (in_elem_bitwidth - 1) as _);
        // Shift the MSB to the right by "in_elem_bitwidth - 1" into the first bit position.
        let shift_indices = vec![shift_idx; in_len as _];