Disallow extending a malformed type (issue 13940).

tests/language/malformed_inheritance_test.dart

Index: tests/language/malformed_inheritance_test.dart
===================================================================
--- tests/language/malformed_inheritance_test.dart	(revision 28477)
+++ tests/language/malformed_inheritance_test.dart	(working copy)
@@ -16,6 +16,12 @@
   extends Object with A<Unresolved> /// 04: static type warning
   implements Unresolved /// 05: compile-time error
   implements A<Unresolved> /// 06: static type warning
+  <A> extends A<int> /// 07: compile-time error
+  <A> extends A<Unresolved> /// 08: compile-time error
+  <A> extends Object with A<int> /// 09: compile-time error
+  <A> extends Object with A<Unresolved> /// 10: compile-time error
+  <A> implements A<int> /// 11: compile-time error
+  <A> implements A<Unresolved> /// 12: compile-time error
 {
 
 }