This is why it works:

2;0 juerd@ouranos:~$ perl -MO=Deparse -e'while () { print "1\n" }'
for (;;) {
    print "1\n";
}
-e syntax OK
[download]

Many people aren't going to like this:

2;0 juerd@ouranos:~$ perl -MO=Deparse -e'while (1) { print "1\n" }'
for (;;) {
    print "1\n";
}
-e syntax OK
[download]

2;0 juerd@ouranos:~$ perl -e'undef christmas'
Segmentation fault
2;139 juerd@ouranos:~$
[download]