package New;
use v5.36;
use Path::UTiny; # imagine a unicode-aware Path::Tiny

# Create directory named "\xC4\x80"
path("\x{100}")->mkdir;

for (path(".")->children) {
  # compares as unicode
  Old->foo($_) if $_->name eq /\x{100}/;
}

package Old;
use v5.36;

sub foo($dir) {
  # stringify to bytes, creates file "\xC4\x80/\x80.txt"
  open my $f, '>', "$dir/\x80.txt";
}