Function sort
pub fn sort<T, F: FnMut(&T, &T) -> bool>(v: &mut [T], scratch: &mut [MaybeUninit<T>], eager_sort: bool, is_less: &mut F)Sorts v based on comparison function is_less. If eager_sort is true,
it will only do small-sorts and physical merges, ensuring O(N * log(N))
worst-case complexity. scratch.len() must be at least
max(v.len() - v.len() / 2, SMALL_SORT_GENERAL_SCRATCH_LEN) otherwise the implementation may abort.
Fully ascending and descending inputs will be sorted with exactly N - 1
comparisons.
This is the main loop for driftsort, which uses powersort's heuristic to determine in which order to merge runs, see below for details.