Ruby

merge revision(s) 57362: [Backport #13096]

    vm_method.c: resolve refined method to undef

    * vm_method.c (rb_undef): resolve the method entry which refines a
      prepended method entry.  [ruby-core:78944] [Bug #13096]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@57862 b2dd03c8-39d4-4d8f-98ff-823fe69b080e