Add ElementKind for factory constructors.

pkg/compiler/lib/src/cps_ir/cps_ir_builder_task.dart

 // Copyright (c) 2013, 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.
 
 library dart2js.ir_builder_task;
 
 import '../closure.dart' as closurelib;
 import '../closure.dart' hide ClosureScope;
 import '../common.dart';
 import '../common/names.dart' show
@@ skipping 2611 matching lines @@
       ir.FunctionDefinition root;
       switch (element.kind) {
         case ElementKind.GENERATIVE_CONSTRUCTOR:
           root = buildConstructor(element);
           break;
 
         case ElementKind.GENERATIVE_CONSTRUCTOR_BODY:
           root = buildConstructorBody(element);
           break;
 
+        case ElementKind.FACTORY_CONSTRUCTOR:
         case ElementKind.FUNCTION:
         case ElementKind.GETTER:
         case ElementKind.SETTER:
           root = buildFunction(element);
           break;
 
         case ElementKind.FIELD:
           if (Elements.isStaticOrTopLevel(element)) {
             root = buildStaticFieldInitializer(element);
           } else {
@@ skipping 934 matching lines @@
     if (compiler.backend.isForeign(function)) {
       return handleForeignCode(node, function, argumentList, callStructure);
     } else {
       return irBuilder.buildStaticFunctionInvocation(function, callStructure,
           translateStaticArguments(argumentList, function, callStructure),
           sourceInformation:
               sourceInformationBuilder.buildCall(node, node.selector));
     }
   }
 }