io.c: fptr_copy_finalizer
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62123 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
io.c: fptr_copy_finalizer
became ordinary file, to fix access after free. to be finalized
by pipe_finalize and being in pipe_list must match.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62123 b2dd03c8-39d4-4d8f-98ff-823fe69b080e