Tweak for the type of the 'instances' variable.

pkg/analysis_server/lib/src/status/get_handler.dart

Index: pkg/analysis_server/lib/src/status/get_handler.dart
diff --git a/pkg/analysis_server/lib/src/status/get_handler.dart b/pkg/analysis_server/lib/src/status/get_handler.dart
index 2d3ffa0dd963593b6fe16fd6f9c4eb70d8602834..9a7aadd46f525ef2edc419f91d6b20f1d9d3f788 100644
--- a/pkg/analysis_server/lib/src/status/get_handler.dart
+++ b/pkg/analysis_server/lib/src/status/get_handler.dart
@@ -1659,7 +1659,7 @@ class GetHandler {
         AnalysisServer server = _server.analysisServer;
         MemoryUseData data = new MemoryUseData();
         data.processAnalysisServer(server);
-        Map<Type, HashSet> instances = data.instances;
+        Map<Type, Set> instances = data.instances;
         List<Type> types = instances.keys.toList();
         types.sort((Type left, Type right) =>
             left.toString().compareTo(right.toString()));