>perl -MO=Deparse -e "open my $fh, $filename || die qq(couldn't open $filename: $!)"
open my $fh, $filename || die("couldn't open ${filename}: $!");
-e syntax OK

>perl -MO=Deparse -e "open my $fh, $filename or die qq(couldn't open $filename: $!)"
die "couldn't open ${filename}: $!" unless open my $fh, $filename;
-e syntax OK