Handle malformed types in catch-on.

tests/language/language.status

Index: tests/language/language.status
diff --git a/tests/language/language.status b/tests/language/language.status
index c64f4c589b832c45200abdb89adca9d8b5ada805..cd003a23c80300b0d5c385b7801d8efe90f5dc6a 100644
--- a/tests/language/language.status
+++ b/tests/language/language.status
@@ -56,6 +56,8 @@ type_annotation_test/09: Fail # Issue 6973
 
 type_parameter_literal_test: Fail # Issue 7551
 
+on_catch_malformed_type_test: Fail # Issue 8601
+
 mixin_illegal_syntax_test/none: Fail
 mixin_type_parameters_mixin_test: Fail
 mixin_type_parameters_super_test: Fail
@@ -349,6 +351,8 @@ type_variable_scope_test: Fail # type arguments on redirecting factory not imple
 many_overridden_no_such_method_test: Fail, Pass, OK # Fails in minified mode, test depends on method names.
 overridden_no_such_method_test: Fail, Pass, OK # Fails in minified mode, test depends on method names.
 
+on_catch_malformed_type_test: Fail # Issue 8601
+
 # Mixins fail on the VM.
 mixin_illegal_syntax_test/none: Fail            # VM issue
 mixin_illegal_constructor_test/none: Fail       # VM issue