perf(map): avoid using .call when there is no context

The most common use case is calling map without context.
In this case, if the iterator function is called directly instead
of using iterator.call, there will be a performance gain.
perf(forEach): avoid using .call when there is no context

The most common use case is calling forEach and forEachSorted
without context. In this case, if the iterator function is called
directly instead of using iterator.call there will be a performance
gain.