Recover from bad supertypes.

tests/language/language_kernel.status

Index: tests/language/language_kernel.status
diff --git a/tests/language/language_kernel.status b/tests/language/language_kernel.status
index 4d5815953b1595ffa55926712874ad61d010def2..3a2da646f49b6e60020518b6109539dce16e2ce2 100644
--- a/tests/language/language_kernel.status
+++ b/tests/language/language_kernel.status
@@ -323,8 +323,6 @@ export_ambiguous_main_negative_test: Crash
 export_double_same_main_test: Crash
 export_main_test: Crash
 export_private_test/01: MissingCompileTimeError
-extend_type_parameter2_negative_test: DartkCrash
-extend_type_parameter_negative_test: DartkCrash
 external_test/11: MissingCompileTimeError
 external_test/12: MissingCompileTimeError
 external_test/13: MissingRuntimeError
@@ -379,7 +377,6 @@ function_type_alias5_test/01: MissingCompileTimeError
 function_type_alias5_test/02: MissingCompileTimeError
 function_type_alias6_test/00: MissingCompileTimeError
 function_type_alias7_test/00: MissingCompileTimeError
-function_type_alias7_test/01: DartkCrash
 function_type_alias7_test/02: MissingCompileTimeError
 function_type_alias9_test/00: MissingCompileTimeError
 function_type_parameter2_negative_test: Crash
@@ -441,12 +438,8 @@ malformed2_test/00: RuntimeError
 malformed_inheritance_test/01: MissingCompileTimeError
 malformed_inheritance_test/03: Crash
 malformed_inheritance_test/05: MissingCompileTimeError
-malformed_inheritance_test/07: DartkCrash
-malformed_inheritance_test/08: DartkCrash
 malformed_inheritance_test/09: MissingCompileTimeError
 malformed_inheritance_test/10: MissingCompileTimeError
-malformed_inheritance_test/11: DartkCrash
-malformed_inheritance_test/12: DartkCrash
 malformed_test/none: RuntimeError
 map_literal2_negative_test: Fail
 map_literal3_test: RuntimeError