Fix for 'hasNoSupertype' for Object when summarize AST.

pkg/analyzer/test/src/summary/summarize_ast_test.dart

Index: pkg/analyzer/test/src/summary/summarize_ast_test.dart
diff --git a/pkg/analyzer/test/src/summary/summarize_ast_test.dart b/pkg/analyzer/test/src/summary/summarize_ast_test.dart
index 4e4cc1ef416f150348c1b2dc222566546b50bb10..c4aa695b81a68764d1196b31d3b666b4e7b43cbd 100644
--- a/pkg/analyzer/test/src/summary/summarize_ast_test.dart
+++ b/pkg/analyzer/test/src/summary/summarize_ast_test.dart
@@ -108,6 +108,13 @@ class UnlinkedSummarizeAstTest extends Object with SummaryTest {
     }
   }
 
+  test_class_no_superclass() {
+    UnlinkedClass cls = serializeClassText('part of dart.core; class Object {}',
+        className: 'Object');
+    expect(cls.supertype, isNull);
+    expect(cls.hasNoSupertype, isTrue);
+  }
+
   CompilationUnit _parseText(String text) {
     CharSequenceReader reader = new CharSequenceReader(text);
     Scanner scanner =