Why would anyone want to use such a .dll like that? Sounds like an ill-conceived concept, "whilefix". There's nothing broken about While.
If you're having a problem with loops taking too long to complete, the problem lies in your approach, not the platform. Consider what data you're trying to access, and how you can access it more efficiently, prefetch, in segments, or whatever translates into the minimum amount of work that's actually necessary.
What is the data you are working with, why do you need to traverse IT ALL, on demand, when?
I have worked with hash tables containing 6 million items. It's not an issue if you plan ahead.