Adding writev support to IO#write_nonblock
In Ruby 2.5 IO#write received writev support (https://github.com/ruby/ruby/commit/3efa7126e5e853f06cdd78d4d88837aeb72a9a3e), allowing it to accept multiple arguments and utilize writev when available.
Would it be possible to add this feature to IO#write_nonblock as well? IO#write_nonblock is used by the HTTP.rb and Socketry gems to implement their "write timeout" feature (the same way that IO#read_nonblock is used in Net::HTTP to implement "read timeout"). Since IO#write_nonblock doesn't yet support writev, at the moment it's not possible for HTTP.rb and Socketry to utilize writev when the "write timeout" is specified.