[ruby/irb] Pass RI options to help

https://github.com/ruby/irb/commit/9b98d1afab

lib/irb/cmd/help.rb

@@ -17,7 +17,8 @@ module IRB
     class Help < Nop
       def execute(*names)
         require 'rdoc/ri/driver'
-        IRB::ExtendCommand::Help.const_set(:Ri, RDoc::RI::Driver.new)
+        opts = RDoc::RI::Driver.process_args([])
+        IRB::ExtendCommand::Help.const_set(:Ri, RDoc::RI::Driver.new(opts))
       rescue LoadError, SystemExit
         IRB::ExtendCommand::Help.remove_method(:execute)
         # raise NoMethodError in ensure