{"ast_node_type":"other","tokens":[{"end":74,"kind":"keyword","start":0,"text":"bx.lifetime_start(scratch.llval,"}]}
                        bx.lifetime_start(scratch.llval, arg.layout.size);
                        let scratch = PlaceValue::alloca(bx, arg.layout.size, required_align);
                        bx.typed_place_copy(scratch, op_place_val, op.layout);