merge revision(s) r45827: [Backport #9618]

	* ext/pathname/lib/pathname.rb (cleanpath_aggressive): make all
	  separators File::SEPARATOR from File::ALT_SEPARATOR.
	  Reported by Daniel Rikowski.
	  Fixed by Nobuyoshi Nakada.  [Bug #9618]

	* ext/pathname/lib/pathname.rb (cleanpath_conservative): ditto.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_1@46911 b2dd03c8-39d4-4d8f-98ff-823fe69b080e