docker, runtime: remove binutils-dev dependency
docker, runtime: remove binutils-dev dependency

We currently still have binutils-dev as a runtime dependency for
bpftool since it ships libbfd which is needed for the JIT disasm.
This is not great since it also pulls in binutils itself as a
dependency and as a result the Cilium runtime image ships with an
assembler, linker, etc:

  root@068f3a5ff554:/cni# ls -l /usr/bin/x86_64*
  lrwxrwxrwx 1 root root       7 Jan  8 18:31 /usr/bin/x86_64 -> setarch
  -rwxr-xr-x 1 root root   31152 May  8  2019 /usr/bin/x86_64-linux-gnu-addr2line
  -rwxr-xr-x 1 root root   59640 May  8  2019 /usr/bin/x86_64-linux-gnu-ar
  -rwxr-xr-x 1 root root  917488 May  8  2019 /usr/bin/x86_64-linux-gnu-as
  -rwxr-xr-x 1 root root   26744 May  8  2019 /usr/bin/x86_64-linux-gnu-c++filt
  -rwxr-xr-x 1 root root 2911496 May  8  2019 /usr/bin/x86_64-linux-gnu-dwp
  -rwxr-xr-x 1 root root   31184 May  8  2019 /usr/bin/x86_64-linux-gnu-elfedit
  lrwxrwxrwx 1 root root      24 May  8  2019 /usr/bin/x86_64-linux-gnu-gold -> x86_64-linux-gnu-ld.gold
  -rwxr-xr-x 1 root root  102120 May  8  2019 /usr/bin/x86_64-linux-gnu-gprof
  lrwxrwxrwx 1 root root      23 May  8  2019 /usr/bin/x86_64-linux-gnu-ld -> x86_64-linux-gnu-ld.bfd
  -rwxr-xr-x 1 root root 1779400 May  8  2019 /usr/bin/x86_64-linux-gnu-ld.bfd
  -rwxr-xr-x 1 root root 3136552 May  8  2019 /usr/bin/x86_64-linux-gnu-ld.gold
  -rwxr-xr-x 1 root root   44184 May  8  2019 /usr/bin/x86_64-linux-gnu-nm
  -rwxr-xr-x 1 root root  235720 May  8  2019 /usr/bin/x86_64-linux-gnu-objcopy
  -rwxr-xr-x 1 root root  414128 May  8  2019 /usr/bin/x86_64-linux-gnu-objdump
  -rwxr-xr-x 1 root root   59672 May  8  2019 /usr/bin/x86_64-linux-gnu-ranlib
  -rwxr-xr-x 1 root root  596440 May  8  2019 /usr/bin/x86_64-linux-gnu-readelf
  -rwxr-xr-x 1 root root   31024 May  8  2019 /usr/bin/x86_64-linux-gnu-size
  -rwxr-xr-x 1 root root   31232 May  8  2019 /usr/bin/x86_64-linux-gnu-strings
  -rwxr-xr-x 1 root root  235728 May  8  2019 /usr/bin/x86_64-linux-gnu-strip

We can build bpftool without binutils-dev just fine, it's just that
we won't get the JIT disasm which is an acceptable tradeoff given we
still have the xlated dump and it's not needed often in prod environment.
Also, we can reduce the Cilium runtime image by another ~20M in size.

Signed-off-by: Daniel Borkmann <3d0f3b9ddcacec30c4008c5e030e6c13a478cb4f@iogearbox.net>

tklauser/cilium,tklauser/cilium,michi-covalent/cilium,tgraf/cilium,tgraf/cilium,tgraf/cilium,tgraf/cilium,michi-covalent/cilium,cilium-team/cilium,michi-covalent/cilium,cilium/cilium,tklauser/cilium,cilium-team/cilium,cilium/cilium,michi-covalent/cilium,cilium/cilium,tgraf/cilium,tklauser/cilium,michi-covalent/cilium,cilium/cilium,tgraf/cilium,cilium/cilium,tklauser/cilium