Introduce ConstructorEntity

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 '../elements/elements.dart';
 import '../elements/entities.dart';
 import '../elements/types.dart';
 import '../native/native.dart' as native;
@@ skipping 16 matching lines @@
   InterfaceType createInterfaceType(
       ir.Class cls, List<ir.DartType> typeArguments);
 
   /// Returns the [CallStructure] corresponding to the [arguments].
   CallStructure getCallStructure(ir.Arguments arguments);
 
   /// Returns the [Selector] corresponding to the invocation or getter/setter
   /// access of [node].
   Selector getSelector(ir.Expression node);
 
-  /// Returns the [FunctionEntity] corresponding to the generative or factory
+  /// Returns the [ConstructorEntity] corresponding to the generative or factory
   /// constructor [node].
-  FunctionEntity getConstructor(ir.Member node);
+  ConstructorEntity getConstructor(ir.Member node);
 
   /// Returns the [MemberEntity] corresponding to the member [node].
   MemberEntity getMember(ir.Member node);
 
   /// Returns the [FunctionEntity] corresponding to the procedure [node].
   FunctionEntity getMethod(ir.Procedure node);
 
   /// Returns the [FieldEntity] corresponding to the field [node].
   FieldEntity getField(ir.Field node);
 
@@ skipping 44 matching lines @@
 }
 
 /// Kinds of foreign functions.
 enum ForeignKind {
   JS,
   JS_BUILTIN,
   JS_EMBEDDED_GLOBAL,
   JS_INTERCEPTOR_CONSTANT,
   NONE,
 }