$ perl junk
Constant subroutine A::VALUE redefined at junk line 12.
Constant is 1

$ perl -MO=Deparse junk
package A;
sub BEGIN {
    require strict;
    do {
        'strict'->import
    };
}
use constant ('VALUE', 1);
sub func {
    use strict 'refs';
    print 'Constant is ', 1, "\n";
}
package main;
sub BEGIN {
    use strict 'refs';
    require strict;
    do {
        'strict'->import
    };
}
*{'A::VALUE';} = sub () { 2 }
;
'A'->func;
junk syntax OK
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