do not suggest local functions

pkg/analysis_server/lib/src/services/completion/dart_completion_cache.dart

Index: pkg/analysis_server/lib/src/services/completion/dart_completion_cache.dart
diff --git a/pkg/analysis_server/lib/src/services/completion/dart_completion_cache.dart b/pkg/analysis_server/lib/src/services/completion/dart_completion_cache.dart
index fb31174f9b6561e8870022ed2bff07ac3832e55e..d8afca40706b15e297f24c3cfa1494ac7718e5a1 100644
--- a/pkg/analysis_server/lib/src/services/completion/dart_completion_cache.dart
+++ b/pkg/analysis_server/lib/src/services/completion/dart_completion_cache.dart
@@ -310,9 +310,15 @@ class DartCompletionCache extends CompletionCache {
    */
   void _addSuggestion(Element element, int relevance) {
     if (element is ExecutableElement) {
+      // Do not suggest operators or local functions
       if (element.isOperator) {
         return;
       }
+      if (element is FunctionElement) {
+        if (element.enclosingElement is! CompilationUnitElement) {
+          return;
+        }
+      }
     }
 
     CompletionSuggestion suggestion =