Segfault after for clause compilation error

Imported from http://bugzilla.roxen.com/bugzilla/show_bug.cgi?id=7397

Reported by Martin Karlgren marty@roxen.com

Test case:

$ bin/pike
Pike v8.0 release 35 running Hilfe v3.5 (Incremental Pike Frontend)
> for (i = 0; 1; i += 1) { }
Segmentation fault: 11