* reg*.c: Merge Onigmo 5.15.0 38a870960aa7370051a3544

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47598 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* 2014-09-16

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47599 b2dd03c8-39d4-4d8f-98ff-823fe69b080e