merge revision(s) r46313: [Backport #9896]

	* eval.c (rb_using_refinement): add write-barriers for
	  cref->nd_refinements.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_1@46524 b2dd03c8-39d4-4d8f-98ff-823fe69b080e