update config files

* .travis.yml (before_script): update config files.
* common.mk ($(srcdir)/tool/config.{guess,sub}): use get-config_files.
* tool/config_files.rb: split get-config_files.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41294 b2dd03c8-39d4-4d8f-98ff-823fe69b080e