Support type argument substitution on unnamed mixin applications.

tests/lib/lib.status

Index: tests/lib/lib.status
diff --git a/tests/lib/lib.status b/tests/lib/lib.status
index 5170a01900c7bac6bce09d0499b6238262148dbc..e1c775599203c82b0bbb80e81dfdfddc84ba197a 100644
--- a/tests/lib/lib.status
+++ b/tests/lib/lib.status
@@ -18,7 +18,7 @@ math/low_test: RuntimeError
 
 mirrors/basic_types_in_dart_core_test: RuntimeError # Issue 14025
 mirrors/class_declarations_test/none: RuntimeError # Issue 13440
-mirrors/closures_test/none: RuntimeError # Issue 6490
+mirrors/closures_test/none: RuntimeError # Issue 6940
 mirrors/constructor_kinds_test: RuntimeError # Issue 13799
 mirrors/constructor_private_name_test: CompileTimeError # Issue 13597
 mirrors/delegate_call_through_getter_test: RuntimeError # Issue 15138
@@ -28,13 +28,11 @@ mirrors/fake_function_without_call_test: RuntimeError # Issue 11612
 mirrors/find_in_context_test: Fail # Issue 6490
 mirrors/find_in_context_private_test: Fail # Issue 6490
 mirrors/find_in_context_fake_function_test: Fail # Issue 6490
-mirrors/function_type_mirror_test: RuntimeError # Issue 12166
-mirrors/generic_f_bounded_mixin_application_test: RuntimeError # Issue 12087
-mirrors/generic_function_typedef_test: RuntimeError # Issue 12333
+mirrors/function_type_mirror_test: RuntimeError # Issue 12785
+mirrors/generic_function_typedef_test: RuntimeError # Issue 12785
 mirrors/generic_interface_test: RuntimeError # Issue 12087
 mirrors/generic_local_function_test: RuntimeError # Issue 12333
 mirrors/generic_mixin_test: RuntimeError # Issue 12333
-mirrors/generic_mixin_applications_test: RuntimeError # Issue 12333
 mirrors/hierarchy_invariants_test: RuntimeError # Issue 15262
 mirrors/immutable_collections_test: RuntimeError # Issue 14030
 mirrors/initializing_formals_test/01: RuntimeError # Issue 6490