Handle generic factory constructors in kernel_impact

pkg/compiler/lib/src/ssa/kernel_ast_adapter.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/values.dart';
@@ skipping 155 matching lines @@
 
   ir.Procedure get mapLiteralConstructor =>
       kernel.functions[_backend.helpers.mapLiteralConstructor];
 
   ir.Procedure get mapLiteralConstructorEmpty =>
       kernel.functions[_backend.helpers.mapLiteralConstructorEmpty];
 
   DartType getDartType(ir.DartType type) {
     return type.accept(_typeConverter);
   }
+
+  List<DartType> getDartTypes(List<ir.DartType> types) {
+    return types.map(getDartType).toList();
+  }
 }
 
 class DartTypeConverter extends ir.DartTypeVisitor<DartType> {
   final KernelAstAdapter astAdapter;
 
   DartTypeConverter(this.astAdapter);
 
   List<DartType> visitTypes(List<ir.DartType> types) {
     return new List.generate(
         types.length, (int index) => types[index].accept(this));
@@ skipping 23 matching lines @@
   @override
   DartType visitDynamicType(ir.DynamicType node) {
     return const DynamicType();
   }
 
   @override
   DartType visitInvalidType(ir.InvalidType node) {
     throw new UnimplementedError("Invalid types not currently supported");
   }
 }