Refactor ConstantExpression/ConstantConstructor to use entities.

pkg/compiler/lib/src/serialization/equivalence.dart

 // Copyright (c) 2016, 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.
 
 /// Functions for asserting equivalence across serialization.
 
 library dart2js.serialization.equivalence;
 
 import '../closure.dart';
 import '../common/resolution.dart';
@@ skipping 792 matching lines @@
 
   @override
   bool visitUnary(UnaryConstantExpression exp1, UnaryConstantExpression exp2) {
     return strategy.test(
             exp1, exp2, 'operator', exp1.operator, exp2.operator) &&
         strategy.testConstants(
             exp1, exp2, 'expression', exp1.expression, exp2.expression);
   }
 
   @override
-  bool visitVariable(
-      VariableConstantExpression exp1, VariableConstantExpression exp2) {
+  bool visitField(FieldConstantExpression exp1, FieldConstantExpression exp2) {
     return strategy.testElements(
         exp1, exp2, 'element', exp1.element, exp2.element);
   }
+
+  @override
+  bool visitLocalVariable(LocalVariableConstantExpression exp1,
+      LocalVariableConstantExpression exp2) {
+    return strategy.testElements(
+        exp1, exp2, 'element', exp1.element, exp2.element);
+  }
 
   @override
   bool visitBool(BoolConstantExpression exp1, BoolConstantExpression exp2) {
     return strategy.test(
         exp1, exp2, 'primitiveValue', exp1.primitiveValue, exp2.primitiveValue);
   }
 
   @override
   bool visitDouble(
       DoubleConstantExpression exp1, DoubleConstantExpression exp2) {
@@ skipping 1287 matching lines @@
 }
 
 bool areMetadataAnnotationsEquivalent(
     MetadataAnnotation metadata1, MetadataAnnotation metadata2) {
   if (metadata1 == metadata2) return true;
   if (metadata1 == null || metadata2 == null) return false;
   return areElementsEquivalent(
           metadata1.annotatedElement, metadata2.annotatedElement) &&
       areConstantsEquivalent(metadata1.constant, metadata2.constant);
 }