Turn on initializing formal access

tests/lib/lib.status

Index: tests/lib/lib.status
diff --git a/tests/lib/lib.status b/tests/lib/lib.status
index ab4f18c897e84ac597e10edb1e44e3b3e81aa108..0f21a8c6841d27eefb7990c500cacf474786b908 100644
--- a/tests/lib/lib.status
+++ b/tests/lib/lib.status
@@ -259,6 +259,7 @@ convert/streamed_conversion_json_utf8_decode_test: Pass, Slow # Infrequent timeo
 async/timer_not_available_test: Fail, OK
 mirrors/native_class_test: Fail, OK # This test is meant to run in a browser.
 mirrors/deferred_type_test: CompileTimeError, OK # Don't have a multitest marker for dynamic compile time errors.
+mirrors/initializing_formals_test/01: Fail # initializing formals are implicitly final as of Dart 1.21
 
 [ $compiler == none || $compiler == precompiler || $compiler == dart2app || $compiler == dart2appjit ]
 async/timer_not_available_test: SkipByDesign # only meant to test when there is no way to implement timer (currently only in d8)