Fix incremental element builder for added enums.

pkg/analyzer/test/src/task/incremental_element_builder_test.dart

Index: pkg/analyzer/test/src/task/incremental_element_builder_test.dart
diff --git a/pkg/analyzer/test/src/task/incremental_element_builder_test.dart b/pkg/analyzer/test/src/task/incremental_element_builder_test.dart
index 9a69798bf55497528af00479b136af5be1817bda..ecd98cbc6212f6231a69dfe5caea5c4ca769ef34 100644
--- a/pkg/analyzer/test/src/task/incremental_element_builder_test.dart
+++ b/pkg/analyzer/test/src/task/incremental_element_builder_test.dart
@@ -1451,6 +1451,14 @@ enum B {B1, B2}
     expect(elementB, isNotNull);
     expect(elementA.name, 'A');
     expect(elementB.name, 'B');
+    expect(elementA.fields.map((f) => f.name),
+        unorderedEquals(['index', 'values', 'A1', 'A2']));
+    expect(elementA.accessors.map((a) => a.name),
+        unorderedEquals(['index', 'values', 'A1', 'A2']));
+    expect(elementB.fields.map((f) => f.name),
+        unorderedEquals(['index', 'values', 'B1', 'B2']));
+    expect(elementB.accessors.map((a) => a.name),
+        unorderedEquals(['index', 'values', 'B1', 'B2']));
     // unit.types
     expect(unitElement.enums, unorderedEquals([elementA, elementB]));
     // verify delta