libck closure contains quite a lot of stuff that we don't need,
but that's best left for another time and perhaps closure doesn't
matter that much for a tool like dnsperf.
Also:
- make fetchSubodules explicit, it is strictly required by pahole
build system until debian efforts to use system libbpf finish:
see https://www.spinics.net/lists/dwarves/msg00732.html
- fix license to gpl2Only as requested by review bot
Without this change `as` on `aarch64-darwin` is defunct:
```
$ /nix/store/g11xba8ch20zndaf32hfnap46z47b5k3-cctools-port-949.0.1/bin/as -v
/nix/store/g11xba8ch20zndaf32hfnap46z47b5k3-cctools-port-949.0.1/bin/as: assembler (/nix/store/g11xba8ch20zndaf32hfnap46z47b5k3-cctools-port-949.0.1/libexec/as/arm64/as or /nix/store/g11xba8ch20zndaf32hfnap46z47b5k3-cctools-port-949.0.1/libexec/as/arm64/as) for architecture arm64 not installed
Installed assemblers are:
/nix/store/g11xba8ch20zndaf32hfnap46z47b5k3-cctools-port-949.0.1/libexec/as/ppc64/as for architecture ppc64
/nix/store/g11xba8ch20zndaf32hfnap46z47b5k3-cctools-port-949.0.1/libexec/as/x86_64/as for architecture x86_64
/nix/store/g11xba8ch20zndaf32hfnap46z47b5k3-cctools-port-949.0.1/libexec/as/ppc/as for architecture ppc
/nix/store/g11xba8ch20zndaf32hfnap46z47b5k3-cctools-port-949.0.1/libexec/as/i386/as for architecture i386
/nix/store/g11xba8ch20zndaf32hfnap46z47b5k3-cctools-port-949.0.1/libexec/as/arm/as for architecture arm
```
Apple defaults to Clang in all cases from what I see, but nixpkgs prefers `cctools`: #51881.
Add an override to configuration-common.nix adding the following
features to the derivation:
* Let test suite discover the built spacecookie binary, so it doesn't
skip integration tests (which are very cheap and take just over 1s).
* Install man pages shipped in the sdist. (If someone is eager to get
rid of this override feel free to explain to me how to achieve this
without a Custom build-type which pulls in thousands of modules from
Cabal. :p)
Mario Rodas