Store subtyped names in Analysis Driver unlinked units.

pkg/analyzer/lib/src/summary/idl.dart

Index: pkg/analyzer/lib/src/summary/idl.dart
diff --git a/pkg/analyzer/lib/src/summary/idl.dart b/pkg/analyzer/lib/src/summary/idl.dart
index d7604a3069d72c3f61e200b7aec1ae7cad6ed9ed..901c5bad796a718b1c29cffd249f768531496465 100644
--- a/pkg/analyzer/lib/src/summary/idl.dart
+++ b/pkg/analyzer/lib/src/summary/idl.dart
@@ -332,6 +332,13 @@ abstract class AnalysisDriverUnlinkedUnit extends base.SummaryClass {
   List<String> get referencedNames;
 
   /**
+   * List of names which are used in `extends`, `with` or `implements` clauses
+   * in the file. Import prefixes and type arguments are not included.
+   */
+  @Id(4)
+  List<String> get subtypedNames;
+
+  /**
    * Unlinked information for the unit.
    */
   @Id(1)