Report errors on repeated interfaces.

tests/co19/co19-dart2js.status

Index: tests/co19/co19-dart2js.status
diff --git a/tests/co19/co19-dart2js.status b/tests/co19/co19-dart2js.status
index 18ffb2123adff1a9c9d4a4823c913f18628967cf..01dd02053ff45193f7aead040c277ed30cf6a123 100644
--- a/tests/co19/co19-dart2js.status
+++ b/tests/co19/co19-dart2js.status
@@ -670,7 +670,6 @@ Language/07_Classes/07_Classes_A04_t21: Fail # Checks that a static operator can
 Language/07_Classes/07_Classes_A04_t22: Fail # Checks that an abstract static operator can't be used in place of a class member definition./
 Language/07_Classes/07_Classes_A04_t24: Fail # Checks that a static abstract getter can't be used in place of a class member definition.
 Language/07_Classes/07_Classes_A04_t25: Fail # Checks that a static abstract setter can't be used in place of a class member definition.
-Language/07_Classes/10_Superinterfaces_A04_t01: Fail # Checks that it is a compile-time error if the same type appears more than once in the implements clause.
 Language/07_Classes/1_Instance_Methods_A02_t02: Fail # Checks that a compile-time error is produced if m1 has fewer named parameters than m2 (1 vs. 0) and neither have any required parameters.
 Language/07_Classes/1_Instance_Methods_A02_t05: Fail # Checks that a compile-time error is produced if m1 has almost the same set of named  parameters as m2 except for one of them having a different name.
 Language/07_Classes/2_Getters_A01_t03: Fail # Checks that a compile-time error is produced if empty formal parameter list is present.