* eval.c (rb_using_module): activate refinements in the ancestors of
  the argument module to support refinement inheritance by
  Module#include.  [ruby-core:55671] [Feature #8571]

* test/ruby/test_refinement.rb: related test.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41719 b2dd03c8-39d4-4d8f-98ff-823fe69b080e