Add a task for computing all constant values in a compilation unit.

pkg/analyzer/lib/src/generated/constant.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.
 
 // This code was auto-generated, is not intended to be edited, and is subject to
 // significant change. Please see the README file for more information.
 
 library engine.constant;
 
 import 'dart:collection';
@@ skipping 882 matching lines @@
  * [ConstantEvaluationTarget].
  */
 class ConstantEvaluationTarget_Annotation implements ConstantEvaluationTarget {
   final AnalysisContext context;
   final Source source;
   final Source librarySource;
   final Annotation annotation;
 
   ConstantEvaluationTarget_Annotation(
       this.context, this.source, this.librarySource, this.annotation);
+
+  @override
+  int get hashCode => JenkinsSmiHash.hash4(context.hashCode, source.hashCode,
+      librarySource.hashCode, annotation.hashCode);
+
+  @override
+  bool operator ==(other) {
+    if (other is ConstantEvaluationTarget_Annotation) {
+      return this.context == other.context &&
+          this.source == other.source &&
+          this.librarySource == other.librarySource &&
+          this.annotation == other.annotation;
+    } else {
+      return false;
+    }
+  }
 }
 
 /**
  * Interface used by unit tests to verify correct dependency analysis during
  * constant evaluation.
  */
 abstract class ConstantEvaluationValidator {
   /**
    * This method is called just before computing the constant value associated
    * with [constant]. Unit tests will override this method to introduce
@@ skipping 4277 matching lines @@
       return BoolState.from(_element == rightElement);
     } else if (rightOperand is DynamicState) {
       return BoolState.UNKNOWN_VALUE;
     }
     return BoolState.FALSE_STATE;
   }
 
   @override
   String toString() => _element == null ? "-unknown-" : _element.name;
 }