* iseq.c (iseqw_mark): as wrapped iseq is isolated from the call
  stack, it needs to take care of its parent and ancestors, so
  that they do not become orphans.  [ruby-core:72620] [Bug #11928]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53514 b2dd03c8-39d4-4d8f-98ff-823fe69b080e