Allow trailing comma in parameter and argument lists.

tests/co19/co19-co19.status

Index: tests/co19/co19-co19.status
diff --git a/tests/co19/co19-co19.status b/tests/co19/co19-co19.status
index d531a08560bd3797d131990081870a4ea2aa671f..79989a564eb1fe83d146e97f7e6498f1ad10079d 100644
--- a/tests/co19/co19-co19.status
+++ b/tests/co19/co19-co19.status
@@ -75,3 +75,14 @@ LibTest/isolate/SendPort/send_A03_t02: Fail # Co19 issue 639
 
 [ $runtime == dartium || $compiler == dart2js ]
 LibTest/async/Future/Future.delayed_A01_t02: Pass, Fail # Issue 15524
+
+[ $compiler == none && ($runtime == vm || $runtime == drt || $runtime == dartium)]
+# Optional trailing commas for argument and parameter lists added to language.
+# https://github.com/dart-lang/co19/issues/68
+Language/Expressions/Function_Invocation/Actual_Argument_List_Evaluation/syntax_t05: MissingCompileTimeError, OK
+Language/Expressions/Method_Invocation/Ordinary_Invocation/syntax_t05: MissingCompileTimeError, OK
+Language/Expressions/Method_Invocation/Ordinary_Invocation/syntax_t10: MissingCompileTimeError, OK
+Language/Expressions/Method_Invocation/Super_Invocation/syntax_t05: MissingCompileTimeError, OK
+Language/Functions/Formal_Parameters/syntax_t04: MissingCompileTimeError, OK
+Language/Functions/Formal_Parameters/syntax_t05: MissingCompileTimeError, OK
+Language/Functions/Formal_Parameters/syntax_t12: MissingCompileTimeError, OK