Ruby » Ruby master

• ext/tk/extconf.rb: support s390x (Thanks to bkabrda) [ruby-trunk - Bug #5465]
• ext/tk/extconf.rb: apply [Backport87 - Backport #5048]
• ext/tk/lib/tk/canvas.rb, ext/tk/sample/demos-{en,jp}/{tree.rb,widget}: fix bug (Thanks to zzak) [ruby-trunk - Bug #8319]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41347 b2dd03c8-39d4-4d8f-98ff-823fe69b080e