[Draft] Migrate to 64-bit index and length

[Glavo]

Currently Traversable and all collection APIs use int for indexes and lengths, so the behavior of these collections when the number of elements exceeds 2147483647 is undefined.

We can’t be constrained by this forever. Since the Foreign Memory API has been delivered, we can easily manage large memory segments exceeding the Integer.MAX_VALUE limit. I think it's time to move away from int and towards long.

Making this change would require modifying a lot of APIs, so we're not in a rush to do it. Here are some of the APIs that will be affected:

• AnyTraversable and its subtypes (include all collections);
• All functional interfaces with indexes (such as IndexedFunction).

I would like to know users' opinions and suggestions on this. (call @ice1000)

[ice1000]

I think 64 bit makes sense. I'm not going to object it