Breaking change for JRuby

[Brockfrancom]

Version 0.5.0 causes a bundle update to fail. https://github.com/ruby/resolv/pull/57/files is the change I suspect broke it.

When the following snippet is ran in a rails console on a Mac, an error is thrown as shown below:

jruby-9.4.6.0 :001 > require 'mkmf'
 => true 
jruby-9.4.6.0 :002 > have_library('iphlpapi', 'GetNetworkParams')
checking for GetNetworkParams() in -liphlpapi... /Users/brock/.rvm/rubies/jruby-9.4.6.0/lib/ruby/stdlib/mkmf.rb:456:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.

I think 'iphlpapi' is a windows library that doesn't exist on Mac.

[hsbt]

I could install resolv-0.5.0.

$ gem i resolv
Successfully installed resolv-0.5.0
1 gem installed

It seems JRuby specific issue, not macOS.

[hsbt]

Building native extensions. This could take a while...
ERROR:  Error installing resolv:
        ERROR: Failed to build gem native extension.

    current directory: /Users/hsbt/.local/share/gem/gems/resolv-0.5.0/ext/win32/resolv
/Users/hsbt/.local/share/rbenv/versions/jruby-9.4.9.0/bin/jruby -I /Users/hsbt/.local/share/rbenv/versions/jruby-9.4.9.0/lib/ruby/stdlib extconf.rb
checking for GetNetworkParams() in -liphlpapi... *** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers.  Check the mkmf.log file for more details.  You may
need configuration options.