Dear Maintainer,

The lintian git repository contains an .a file, but it is missing
in the source tarball:

```
$ find -name '*.a'
./t/recipes/checks/unpack/not-an-ar-archive/build-spec/orig/text-file.a
$ tar -tf ../lintian_2.135.1.tar.xz | grep '\.a$'
```

Control: clone -1 -2
Control: reassign -2 src:dpkg
Control: found -2 1.23.7
Control: retitle -2 dpkg-source skips `.a` files in orig tarball for 3.0 (native) source format

This is due to dpkg itself, as it drops `.a` from final tar, see

https://github.com/guillemj/dpkg/commit/ddf788627634080a39931061af354d8d8e15c433

Guillem, this is probably intended in dpkg. However, this was actually added in lintian
because of https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1120737

Do you think it'd make sense to drop `*.a` for dpkg-source only if it is really an
archive file and otherwise not?

If you disagree, would you consider to provide an option to ignore
individual options in default ignore list?

Currently there is `--tar-ignore` which will completely throw away the default
list. It'd be beneficial if there is instead a way to ignore some of these default
entries.

Thanks,
Nilesh