pkg/front_end/testcases/inference/generic_methods_infer_js_builtin.dart:13:5: Context: Write to y@427
  y = "world";
    ^
pkg/front_end/testcases/inference/generic_methods_infer_js_builtin.dart:14:5: Context: Write to y@427
  y = /*error:INVALID_ASSIGNMENT*/ 42;
    ^