Adds generator support for Xcode 5 xctest targets.

test/mac/xctest/MyClass.m

Index: test/mac/xctest/MyClass.m
diff --git a/test/prune_targets/lib1.cc b/test/mac/xctest/MyClass.m
similarity index 76%
copy from test/prune_targets/lib1.cc
copy to test/mac/xctest/MyClass.m
index 692b7de6d82c927503c21607863f671307fa6cd1..699654aa433f8bed0aed077ce27a8d02ad5353e2 100644
--- a/test/prune_targets/lib1.cc
+++ b/test/mac/xctest/MyClass.m
@@ -1,6 +1,7 @@
 // Copyright (c) 2013 Google Inc. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
+#import "MyClass.h"
 
-void libfunc1() {
-}
+@implementation MyClass
+@end