It works for me here, when invoked as perl davido.pl, using ActiveState 5.8.0, with or without the shebang. Also works with -w but in that case spits a bunch of warnings in addition to the intended text.

$;=sub{$/};@;=map{my($a,$b)=($_,$;);$;=sub{$a.$b->()}}
split//,".rekcah lreP rehtona tsuJ";$\=$ ;->();print$/
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