I will handle the PR, but there are a few changes in JRuby's copy of resolv.rb that should be safe to import.

• Platform checks should use RbConfig, not RUBY_PLATFORM (which is always "java" on JRuby)
• Some alternate dealing with IPAddr and such that I will investigate (ideally no change needed here and we fix JRuby)

https://gist.github.com/headius/a78601ac43de2607a4428315a0c4a988