[ruby/rdoc] Fix RDoc::Parser::Ruby not being documented

The calls to require prevent the class from being documented.

https://github.com/ruby/rdoc/commit/76283fc42e

lib/rdoc/parser/ruby.rb

@@ -8,6 +8,9 @@
 #       by Keiju ISHITSUKA (Nippon Rational Inc.)
 #
 
+require 'ripper'
+require_relative 'ripper_state_lex'
+
 ##
 # Extracts code elements from a source file returning a TopLevel object
 # containing the constituent file elements.
@@ -138,9 +141,6 @@
 # Note that by default, the :method: directive will be ignored if there is a
 # standard rdocable item following it.
 
-require 'ripper'
-require_relative 'ripper_state_lex'
-
 class RDoc::Parser::Ruby < RDoc::Parser
 
   parse_files_matching(/\.rbw?$/)