Emulate class and class loader methods

[CalebFenton]

The methods:

• Ljava/lang/Class;->getClassLoader()Ljava/lang/ClassLoader;
• Ljava/security/AccessController;->doPrivileged(Ljava/security/PrivilegedAction;)Ljava/lang/Object;
• Ljava/lang/Class;->newInstance()Ljava/lang/Object;
• Ljava/lang/ClassLoader;->loadClass(Ljava/lang/String;)Ljava/lang/Class;

The getClassLoader can probably just wrap around smalivm's SmaliClassLoader since it knows of all input smali classes. The rest don't look too tricky (read: technically impossible).

Reference: https://github.com/CalebFenton/simplify/issues/52