Complete latest spec changes regarding malformed types (see issue 14006).

tests/language/instanceof3_test.dart

Index: tests/language/instanceof3_test.dart
===================================================================
--- tests/language/instanceof3_test.dart	(revision 29871)
+++ tests/language/instanceof3_test.dart	(working copy)
@@ -23,23 +23,21 @@
     bool got_type_error = false;
     var x = null;
     try {
-      Expect.isTrue(x is UndeclaredType);  // x is null.
+      x is UndeclaredType;  // x is null.
     } on TypeError catch (error) {
       got_type_error = true;
     }
-    // No type error.
-    Expect.isFalse(got_type_error);
+    Expect.isTrue(got_type_error);
   }
   {
     bool got_type_error = false;
     var x = 1;
     try {
-      Expect.isTrue(x is UndeclaredType);  // x is not null.
+      x is UndeclaredType;  // x is not null.
     } on TypeError catch (error) {
       got_type_error = true;
     }
-    // No type error.
-    Expect.isFalse(got_type_error);
+    Expect.isTrue(got_type_error);
   }
   {
     bool got_type_error = false;