$ perl -MO=Deparse -e 'use constant ONE => 1; if (ONE) { print ONE if ONE }'
use constant ('ONE', 1);
do {
    print 1
};
-e syntax OK

$ perl -MO=Deparse -e 'use v5.36; use constant ONE => 1; if (ONE) { print ONE if ONE }'
sub BEGIN {
    require v5.36;
    ()
}
use warnings;
use strict;
no feature ':all';
use feature ':5.36';
use constant ('ONE', 1);
do {
    print 1
};
-e syntax OK