`doesNotRecognizeSelector` after removing hooks of subclass

[JerryChu]

sample project: Aspect_issue.zip

1. add a hook for superclass, e.g. UIViewController

   [UIViewController aspect_hookSelector:@selector(viewDidAppear:) withOptions:AspectPositionAfter usingBlock:^(id<AspectInfo> info) {
       NSLog(@"hooked viewDidAppear!");
   } error:NULL];

2. add a hook for subclass, e.g. ViewController

    id<AspectToken> token = [ViewController aspect_hookSelector:@selector(foo) withOptions:AspectPositionAfter usingBlock:^(id<AspectInfo> info) {
        NSLog(@"hooked foo!");
    } error:NULL];

3. remove the hook of subclass

    [token remove];

Then, when ViewController's [super viewDidAppear:] is called, it will trigger a doesNotRecognizeSelector crash.

It is because that when the hook token is removed from ViewController, Aspect finds ViewController has no hooks, so aspect_undoSwizzleForwardInvocation is called, resetting ViewController's forwardInvocation to the original method (which is nil, and Aspect uses NSObject's forwardInvocation implementation instead ).