Generate the proper error when a constant refers to itself.

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

 // Copyright (c) 2015, 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.src.task.dart_test;
 
 import 'package:analyzer/src/context/cache.dart';
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/constant.dart';
 import 'package:analyzer/src/generated/element.dart';
@@ skipping 1294 matching lines @@
         expect(outputs[CONSTANT_VALUE], same(target));
         EvaluationResultImpl evaluationResult =
             (annotation.elementAnnotation as ElementAnnotationImpl).evaluationResult;
         return evaluationResult;
       }
     }
     fail('Annotation not found');
     return null;
   }
 
-  fail_circular_reference_one_element() {
-    // See dartbug.com/23490.
-    _checkCircularities('x', [], 'const x = x;');
-  }
-
   test_annotation_with_args() {
     Source source = newSource('/test.dart', '''
 const x = 1;
 @D(x) class C {}
 class D {
   const D(this.value);
   final value;
 }
 ''');
     // First compute the resolved unit for the source.
@@ skipping 32 matching lines @@
     expect(evaluationResult.value.intValue, 1);
   }
 
   test_circular_reference() {
     _checkCircularities('x', ['y'], '''
 const x = y + 1;
 const y = x + 1;
 ''');
   }
 
+  test_circular_reference_one_element() {
+    // See dartbug.com/23490.
+    _checkCircularities('x', [], 'const x = x;');
+  }
+
   test_circular_reference_strongly_connected_component() {
     // When there is a circularity, all elements in the strongly connected
     // component should be marked as having an error.
     _checkCircularities('a', ['b', 'c', 'd'], '''
 const a = b;
 const b = c + d;
 const c = a;
 const d = a;
 ''');
   }
@@ skipping 1075 matching lines @@
   /**
    * Fill [errorListener] with [result] errors in the current [task].
    */
   void _fillErrorListener(ResultDescriptor<List<AnalysisError>> result) {
     List<AnalysisError> errors = task.outputs[result];
     expect(errors, isNotNull, reason: result.name);
     errorListener = new GatheringErrorListener();
     errorListener.addAll(errors);
   }
 }