Handle fields with initializers in kernel_impact

pkg/compiler/lib/src/ssa/kernel_impact.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.
 
 import 'package:kernel/ast.dart' as ir;
 
 import '../common.dart';
 import '../common/names.dart';
 import '../compiler.dart';
 import '../constants/expressions.dart';
@@ skipping 65 matching lines @@
   void checkFunctionTypes(ir.FunctionNode node) {
     checkType(node.returnType);
     node.positionalParameters.forEach((v) => checkType(v.type));
     node.namedParameters.forEach((v) => checkType(v.type));
   }
 
   ResolutionImpact buildField(ir.Field field) {
     checkType(field.type);
     if (field.initializer != null) {
       visitNode(field.initializer);
+      if (!field.isConst) {
+        impactBuilder.registerFeature(Feature.LAZY_FIELD);
+      }
     } else {
       impactBuilder.registerFeature(Feature.FIELD_WITHOUT_INITIALIZER);
     }
     return impactBuilder;
   }
 
   ResolutionImpact buildProcedure(ir.Procedure procedure) {
     if (procedure.kind == ir.ProcedureKind.Method ||
         procedure.kind == ir.ProcedureKind.Operator) {
       checkFunctionTypes(procedure.function);
@@ skipping 223 matching lines @@
     } else {
       impactBuilder.registerFeature(Feature.LOCAL_WITHOUT_INITIALIZER);
     }
   }
 
   // TODO(johnniwinther): Make this throw and visit child nodes explicitly
   // instead to ensure that we don't visit unwanted parts of the ir.
   @override
   void defaultNode(ir.Node node) => node.visitChildren(this);
 }