Show prerequisites for compile task

gems/lib/rake/extensiontask.rb

@@ -1,8 +1,9 @@
 module Rake
   class ExtensionTask < TaskLib
     def initialize(...)
-      task :compile do
+      task :compile do |args|
         puts "Dummy `compile` task defined in #{__FILE__}"
+        puts "#{args.name} => #{args.prereqs.join(' ')}"
       end
     end
   end