memory hog script crashes bash with segfault

[Konstantin Khlebnikov]

$ ./bash -c ":(){ : $@$@;};: :"
Segmentation fault

$ ./bash --version
GNU bash, version 4.3.42(1)-release (x86_64-unknown-linux-gnu)
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>

This is free software; you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.