Add tests for indexing.

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 9f80d09110f457bd36705425b8087b857c7486b4..bac32a908efefd47814fdf2c25316eef77235550 100644
--- a/pkg/analyzer/lib/src/summary/idl.dart
+++ b/pkg/analyzer/lib/src/summary/idl.dart
@@ -131,6 +131,31 @@ abstract class EntityRef extends base.SummaryClass {
 }
 
 /**
+ * Enum used to indicate the kind of element in [PackageIndex].
+ */
+enum IndexElementKind {
+  /**
+   * The element itself.

[Paul Berry, 2016/02/26 19:02:05]

I'm confused.  How can the "kind" of an element be the element itself?  What is
this used for?

+   */
+  element,
+
+  /**
+   * The unnamed synthetic constructor a class element.
+   */
+  constructor,
+
+  /**
+   * The getter of a property introducing element.
+   */
+  getter,
+
+  /**
+   * The setter of a property introducing element.
+   */
+  setter
+}
+
+/**
  * Enum used to indicate the kind of index relation.
  */
 enum IndexRelationKind {
@@ -437,6 +462,13 @@ abstract class PackageIndex extends base.SummaryClass {
       generated.readPackageIndex(buffer);
 
   /**
+   * Each item of this list corresponds to a unique referenced element.  It is
+   * the kind of the element.
+   */
+  @Id(6)
+  List<IndexElementKind> get elementKinds;
+
+  /**
    * Each item of this list corresponds to a unique library URI with an element
    * referenced in the [PackageIndex].  It is an index into [uris] list.
    */