{"ast_node_type":"variable","tokens":[{"end":89,"kind":"keyword","start":0,"text":"let"}]}
            let mask_value = bx.context.new_vector_access(None, mask, index).to_rvalue();
            mask_types.push(bx.context.new_field(None, bx.i32_type, "m"));
            let mask_value_cast = bx.context.new_cast(None, mask_value, bx.i32_type);