Add UnlinkedClass.hasNoSupertype property to summaries.

pkg/analyzer/tool/summary/idl.dart

Index: pkg/analyzer/tool/summary/idl.dart
diff --git a/pkg/analyzer/tool/summary/idl.dart b/pkg/analyzer/tool/summary/idl.dart
index 6270573258779ece6d8e017a5361ac0be9606fc4..1742278c973435801cf5c42905091a7b8a8d269a 100644
--- a/pkg/analyzer/tool/summary/idl.dart
+++ b/pkg/analyzer/tool/summary/idl.dart
@@ -229,6 +229,12 @@ class UnlinkedClass {
    * Indicates whether the class is declared using mixin application syntax.
    */
   bool isMixinApplication;
+
+  /**
+   * Indicates whether this class is the core "Object" class (and hence has no
+   * supertype)
+   */
+  bool hasNoSupertype;
 }
 
 /**