Fix ParameterMirror.hasDefaultValue/defaultValue in source mirrors.

tests/lib/lib.status

Index: tests/lib/lib.status
diff --git a/tests/lib/lib.status b/tests/lib/lib.status
index 56787b1df7b741d9070f234425dcd503028328d7..cea9b5bd9b89724c2002198b236955e062a1126b 100644
--- a/tests/lib/lib.status
+++ b/tests/lib/lib.status
@@ -92,6 +92,7 @@ mirrors/variable_is_const_test/none: RuntimeError # Issue 14671
 mirrors/variable_is_const_test/01: MissingCompileTimeError # Issue 5519
 mirrors/list_constructor_test/01: RuntimeError # Issue 13523
 mirrors/raw_type_test/01: RuntimeError # http://dartbug.com/6490
+mirrors/mirrors_reader_test: RuntimeError # Issue 16589
 
 [ $runtime == safari ]
 typed_data/setRange_2_test: Fail # Safari doesn't fully implement spec for TypedArray.set
@@ -227,6 +228,9 @@ mirrors/toplevel_members_test/01: RuntimeError # Issue 14632
 
 async/timer_not_available_test: SkipByDesign # only meant to test when there is no way to implement timer (currently only in d8)
 
+[ $compiler == none && $checked ]
+mirrors/mirrors_reader_test: RuntimeError # Issue 16588
+
 [ $compiler == none && ( $runtime == drt || $runtime == dartium ) ]
 async/schedule_microtask6_test: Fail # Issue 10910
 mirrors/immutable_collections_test: Pass, Slow # Dartium debug uses -O0