Make ninja work with XCTests for iOS.

test/ios/xctests/App/AppDelegate.h

Index: test/ios/xctests/App/AppDelegate.h
diff --git a/test/win/importlib/dll_no_exports.cc b/test/ios/xctests/App/AppDelegate.h
similarity index 53%
copy from test/win/importlib/dll_no_exports.cc
copy to test/ios/xctests/App/AppDelegate.h
index 96dd7970b7145087624aa7b1326ef9a3a0906824..359af8d0530451442ea7b68007c193a3698acd5d 100644
--- a/test/win/importlib/dll_no_exports.cc
+++ b/test/ios/xctests/App/AppDelegate.h
@@ -2,8 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include <windows.h>
+#import <UIKit/UIKit.h>
 
-BOOL APIENTRY DllMain(HMODULE module, DWORD reason, LPVOID reserved) {
-  return TRUE;
-}
+@interface AppDelegate : UIResponder<UIApplicationDelegate>
+
+@property(strong, nonatomic) UIWindow* window;
+
+@end