Refactor `last_file_upwards` to not build an intermmediate array
Refactor `last_file_upwards` to not build an intermmediate array

jmks/rubocop,jmks/rubocop,maxjacobson/rubocop,jmks/rubocop,tdeo/rubocop,maxjacobson/rubocop,rrosenblum/rubocop,tdeo/rubocop,tejasbubane/rubocop,tejasbubane/rubocop,rrosenblum/rubocop,maxjacobson/rubocop,tdeo/rubocop,bbatsov/rubocop,rrosenblum/rubocop,bbatsov/rubocop,tejasbubane/rubocop