* dir.c: Add example for Dir.pwd in Dir.getwd doc by @jasonrclark [fix GH-504]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44677 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

dir.c

@@ -906,6 +906,7 @@ rb_dir_getwd(void)
  *
  *     Dir.chdir("/tmp")   #=> 0
  *     Dir.getwd           #=> "/tmp"
+ *     Dir.pwd             #=> "/tmp"
  */
 static VALUE
 dir_s_getwd(VALUE dir)