Consider renaming BaseElement::as_int to BaseElement::to_u64 #387
Description
I never realized until recently that BaseElement::as_int is not actually a zero-cost operation, but actually does a non-zero-cost operation (montgomery reduction).
This is because the as_ prefix suggests that the cost of the operation is zero-cost, according to the widely used Rust naming conventions. This may seem like a small thing, but naming shapes the mental model and I was happily using as_int everywhere because I assumed it was zero-cost.
According to that guideline, this should instead use the to_ prefix. In that case we'd have to change the signature from &self to self to avoid triggering clippy::wrong_self_convention. That shouldn't affect the API, since BaseElement is Copy anyway.
If we rename this, I think it would be good to choose a more precise name as well and call it to_u64, because it returns a u64 whereas int suggests something more generic, but that's a small thing that just neatly fits into the larger issue.