Compute NativeBasicData for KernelWorldBuilder

pkg/compiler/lib/src/kernel/element_adapter.dart

 // Copyright (c) 2017, 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 '../constants/constructors.dart';
 import '../constants/expressions.dart';
@@ skipping 175 matching lines @@
   }
 
   Selector getSetterSelector(ir.Name irName) {
     Name name = new Name(
         irName.name, irName.isPrivate ? getLibrary(irName.library) : null);
     return new Selector.setter(name);
   }
 
   /// Converts [annotations] into a list of [ConstantExpression]s.
   List<ConstantExpression> getMetadata(List<ir.Expression> annotations) {
+    if (annotations.isEmpty) return const <ConstantExpression>[];
     List<ConstantExpression> metadata = <ConstantExpression>[];
     annotations.forEach((ir.Expression node) {
       ConstantExpression constant = new Constantifier(this).visit(node);
       if (constant == null) {
         throw new UnsupportedError(
             'No constant for ${DebugPrinter.prettyPrint(node)}');
       }
       metadata.add(constant);
     });
     return metadata;
@@ skipping 399 matching lines @@
     }
     if (isRedirecting) {
       return new RedirectingGenerativeConstantConstructor(
           defaultValues, superConstructorInvocation);
     } else {
       return new GenerativeConstantConstructor(
           type, defaultValues, fieldMap, superConstructorInvocation);
     }
   }
 }