`reg*` affects `doc/regexp.rdoc`, but it is not a file of the Oniguruma/Onigmo regular expression engine.
`reg*.[ch]` matches `reg*` except `doc/regexp.rdoc`.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67321 b2dd03c8-39d4-4d8f-98ff-823fe69b080e