do not suggest completions for empty dot target

pkg/analysis_server/test/services/completion/optype_test.dart

Index: pkg/analysis_server/test/services/completion/optype_test.dart
diff --git a/pkg/analysis_server/test/services/completion/optype_test.dart b/pkg/analysis_server/test/services/completion/optype_test.dart
index 70c4f58290d5c2af40929d4d1d3dfd9da2591c98..041af139721849546ea768a2413e4e8e6382e6ab 100644
--- a/pkg/analysis_server/test/services/completion/optype_test.dart
+++ b/pkg/analysis_server/test/services/completion/optype_test.dart
@@ -1054,6 +1054,24 @@ class C2 {
     assertOpType(invocation: true);
   }
 
+  test_PropertyAccess_noTarget() {
+    // SimpleIdentifier  PropertyAccess  ExpressionStatement
+    addTestSource('main() {.^}');
+    assertOpType();
+  }
+
+  test_PropertyAccess_noTarget2() {
+    // SimpleIdentifier  PropertyAccess  CascadeExpressions
+    addTestSource('main() {.^.}');
+    assertOpType();
+  }
+
+  test_PropertyAccess_noTarget3() {
+    // SimpleIdentifier  PropertyAccess  CascadeExpressions
+    addTestSource('main() {..^}');
+    assertOpType();
+  }
+
   test_PropertyAccess_selector() {
     // SimpleIdentifier  PropertyAccess  ExpressionStatement  Block
     addTestSource('class A {a() {"hello".length.^}}');