Enabling AdHoc Networking on ICS to Connect to AdHoc Devices I'm looking for a way to connect my Galaxy Nexus (Android 4.0.x) to my laptop via adhoc wifi. (The laptop will act as my wireless NAS.)

The WiFi Ad Hoc enabler for Android does not work on the Galaxy Nexus. (The statistics at at that link show 0 successes and 13 failures for GNex owners who tried it. However, it works for many other devices.)

I also see this advice:
You need a modified wpa_supplicant file in /system/bin. 

What modifications are needed to the wpa_supplicant file in /system/bin?

I see a couple proposed solutions for other devices, but nothing for the Galaxy Nexus.

https://android.stackexchange.com/a/19133/12444
https://android.stackexchange.com/a/4147/12444
http://www.slatedroid.com/topic/2973-ad-hoc-network/  

However, I see this response: "patching the wpa_suplicant isn't generic and frankly I'd call that method useless."

What is the best solution? Can anyone shed more light on the problem here?
If you can tether mobile data of your Galaxy Nexus over Wi-Fi, you have full-featured ad-hoc network. If you are not sure, install Wireless Tether (root access is required).
After connecting Laptop to this MobileAP, look for IPs of client and Default Gateway (ipconfig /all cmd command works fine with Windows; Fing can also be used). IP of Default Gateway is IP of your Android device. You can use these IPs in any networking service you want. It works.

Another Approach
In ad-hoc networking, it doesn't matter which point is broadcasting SSID. So, you can make your laptop virtual router too. Connect your Galaxy Nexus to it &amp; do whatever you want.
To make your laptop virtual router with NAS support, I'd recommend you to install Connectify Pro (not free). There's a nice free alternative too: mHotspot. After connecting your Galaxy Nexus to virtual hotspot created by it, you can use any networking service over it.