Revert "Handle fields with initializers in constant constructors."

pkg/compiler/lib/src/constants/constant_constructors.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.
 
 // TODO(johnniwinther): Remove this library when all constant constructors are
 // computed during resolution.
 library dart2js.constants.constant_constructors;
 
 import '../common.dart';
 import '../dart_types.dart';
@@ skipping 69 matching lines @@
   ConstantConstructor visitGenerativeConstructorDeclaration(
       FunctionExpression node,
       ConstructorElement constructor,
       NodeList parameters,
       NodeList initializers,
       Node body,
       _) {
     applyParameters(parameters, _);
     ConstructedConstantExpression constructorInvocation =
         applyInitializers(node, _);
-    constructor.enclosingClass.forEachInstanceField((_, FieldElement field) {
-      if (!fieldMap.containsKey(field)) {
-        fieldMap[field] = field.constant;
-      }
-    });
     return new GenerativeConstantConstructor(
         currentClass.thisType, defaultValues, fieldMap, constructorInvocation);
   }
 
   ConstantConstructor visitRedirectingGenerativeConstructorDeclaration(
       FunctionExpression node,
       ConstructorElement constructor,
       NodeList parameters,
       NodeList initializers,
       _) {
@@ skipping 234 matching lines @@
   ConstantExpression visitNamedArgument(NamedArgument node) {
     return apply(node.expression);
   }
 
   @override
   ConstantExpression visitIfNull(Send node, Node left, Node right, _) {
     return new BinaryConstantExpression(
         apply(left), BinaryOperator.IF_NULL, apply(right));
   }
 }