optparse.rb: no duplicate strings

* lib/optparse.rb (OptionParser#parse_in_order): get rid of making
  duplicate strings; $1 and others make a new string each times.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55227 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/optparse.rb

@@ -1547,7 +1547,8 @@ XXX
 
         # short option
         when /\A-(.)((=).*|.+)?/m
-          opt, has_arg, eq, val, rest = $1, $3, $3, $2, $2
+          eq, rest, opt = $3, $2, $1
+          has_arg, val = eq, rest
           begin
             sw, = search(:short, opt)
             unless sw