Solves the problem of .cxx_destruct methods not being called when zombies are enabled

NSObject+ARCZombie.m

#import <objc/runtime.h>

@implementation NSObject (ARCZombie)

+ (void) load
{
	const char *NSZombieEnabled = getenv("NSZombieEnabled");
	if (NSZombieEnabled && tolower(NSZombieEnabled[0]) == 'y')
	{
		Method dealloc = class_getInstanceMethod(self, @selector(dealloc));
		Method arczombie_dealloc = class_getInstanceMethod(self, @selector(arczombie_dealloc));
		method_exchangeImplementations(dealloc, arczombie_dealloc);
	}
}

- (void) arczombie_dealloc
{
	Class aliveClass = object_getClass(self);
	[self arczombie_dealloc];
	Class zombieClass = object_getClass(self);
	
	object_setClass(self, aliveClass);
	objc_destructInstance(self);
	object_setClass(self, zombieClass);
}

@end

This bug should be fixed in iOS 6 and OS X 10.8 according to Technical Q&A QA1758.