fix completion after dot-keyword - fixes #23882

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

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library test.services.completion.target;
 
 import 'package:analysis_server/src/services/completion/completion_target.dart';
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
@@ skipping 121 matching lines @@
     addTestSource('class A {var b; X _c; foo() {var a; (a as ^String).foo();}');
     assertTarget('String', 'a as String');
   }
 
   test_Block() {
     // Block
     addTestSource('main() {^}');
     assertTarget('}', '{}');
   }
 
+  test_Block_keyword() {
+    addTestSource('class C { static C get instance => null; } main() {C.in^}');
+    assertTarget('in', 'C.in');
+  }
+
+  test_Block_keyword2() {
+    addTestSource('class C { static C get instance => null; } main() {C.i^n}');
+    assertTarget('in', 'C.in');
+  }
+
   test_FormalParameter_partialType() {
     // SimpleIdentifier  PrefixedIdentifier  TypeName
     addTestSource('foo(b.^ f) { }');
     assertTarget('f', 'b.f');
   }
 
   test_FormalParameter_partialType2() {
     // SimpleIdentifier  PrefixedIdentifier  TypeName
     addTestSource('foo(b.z^ f) { }');
     assertTarget('z', 'b.z');
@@ skipping 388 matching lines @@
     addTestSource('main() {int b^ = 1;}');
     assertTarget('b = 1', 'int b = 1');
   }
 
   test_VariableDeclaration_lhs_identifier_before() {
     // VariableDeclaration  VariableDeclarationList
     addTestSource('main() {int ^b = 1;}');
     assertTarget('b = 1', 'int b = 1');
   }
 }