Is it valid that {Long,Float,Double}{First,Last} aggregator factories return the same comparator from getComprator()

Shouldn't they return inverse comparators?

@nishantmonu51 @gianm

Start by locating the Long, Float, and Double First/Last aggregator factories and their getComprator() implementations. Compare the comparator behavior across these factories and determine the expected ordering for each case. Done means the comparator semantics are verified and any required correction is covered by the project's existing validation.

Written by the indexing model from the issue text.