vm_insnhelper.c: boudn method transplanting

* vm_insnhelper.c (vm_search_super_method): allow bound method from a
  module, yet another method transplanting.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44553 b2dd03c8-39d4-4d8f-98ff-823fe69b080e