merge revision(s) 57640: [Backport #13214]
fileutils.rb: do not make root * lib/fileutils.rb (FileUtils#mkdir_p): no need to make root directory which should be exist and cannot be made with mkdir recent Cygwin can make a directory contains a colon. [Bug #13214]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_3@58180 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) 57640: [Backport #13214]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_3@58180 b2dd03c8-39d4-4d8f-98ff-823fe69b080e