Just to pass ci of regression fix#19126.
I'll return to this later.
Currently can't reproduce on my Windows wm, here I'm failing on symlink creation
in ci fails later in the process.
Like in issue #18089, this tar contains, same file name in two case
sensitive name version. Unpack should fail on case insensitive file
systems and succeed on case sensitive.
$ tar tvf 18089.tar
18089/
18089/alacritty/
18089/alacritty/darkermatrix.yml
18089/alacritty/Darkermatrix.yml
Running fuzzing tar test with [zig std lib
fuzzing](https://github.com/squeek502/zig-std-lib-fuzzing) reached and
assert in tar implementation. Assert (in std lib) should not be
reachable by external input, so I'm fixing this to return error.
Itarator has `next` function, iterates over tar files. When using from
outside of module with `tar.` prefix makes more sense.
var iter = tar.iterator(reader, null);
while (try iter.next()) |file| {
...
}
