Don't run transformers on classes with @Mixin annotation

[Tommsy64]

No description provided.

[LeonPhilips]

This makes sense: I saw it wasn't ready for review, do you need more time to work on it? Thank you for contributing, by the way!

[Tommsy64]

I made this PR with #7 in mind and realized that it would not fix it as the transformers will still run on inner classes within @Mixin annotated classes. I started writing logic for recursively examining for outer classes; however, I'm misunderstanding something about how ASM handles outer classes, so this isn't working yet.

    public static boolean isMixin(ClassNode classNode) throws IOException {
        if (hasMixinAnnotation(classNode)) {
            return true;
        }
        while (classNode.outerClass != null) {
            String remappedName = FMLDeobfuscatingRemapper.INSTANCE.unmap(classNode.outerClass);
            byte[] outerBytes = TickCentral.LOADER.getClassLoader().getClassBytes(remappedName);
            if (outerBytes == null) {
                TickCentral.LOGGER.warn("Unable to get outer class as resource: " + classNode.outerClass + " (" + FMLDeobfuscatingRemapper.INSTANCE.map(remappedName) + ") Do you have a broken installation? It is referenced in " + classNode.name + " (" + FMLDeobfuscatingRemapper.INSTANCE.map(classNode.name) + ")");
                return false;
            }
            classNode = new ClassNode();
            ClassReader outerReader = new ClassReader(outerBytes);
            outerReader.accept(classNode, ClassReader.SKIP_CODE);
            if (hasMixinAnnotation(classNode)) {
                return true;
            }
        }
        return false;
    }