Regenerate with racc 1.8.1

    * lib/ridl/parser.rb:

lib/ridl/parser.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 #
 # DO NOT MODIFY!!!!
-# This file is automatically generated by Racc 1.8.0
+# This file is automatically generated by Racc 1.8.1
 # from Racc grammar file "parser.ry".
 #
 
@@ -24,7 +24,7 @@
 $".push "#{__dir__}/racc/info.rb"
 
 module Racc
-  VERSION   = '1.8.0'
+  VERSION   = '1.8.1'
   Version = VERSION
   Copyright = 'Copyright (c) 1999-2006 Minero Aoki'
 end
@@ -39,7 +39,7 @@ class ParseError < StandardError; end
   ParseError = Racc::ParseError # :nodoc:
 end
 
-# Racc is a LALR(1) parser generator.
+# Racc is an LALR(1) parser generator.
 # It is written in Ruby itself, and generates Ruby programs.
 #
 # == Command-line Reference