* vm_insnhelper.c (rb_vm_rewrite_cref_stack): copy nd_refinements
	  of orignal crefs. It fixes segmentation fault when calling
	  refined method in duplicate module. [ruby-dev:48878] [Bug #10885]

	* vm_core.h, class.c: change accordingly.

	* test/ruby/test_refinement.rb: add a test for above.
	  of original crefs. It fixes segmentation fault when calling


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_2@49708 b2dd03c8-39d4-4d8f-98ff-823fe69b080e