New review comment by unspecd on void-packages repository

https://github.com/void-linux/void-packages/pull/29382#discussion_r627461382

Comment:
> The cross gdbs are missing gdbserver now

```console
$ ./xbps-src pkg avr-gdb
...
/builddir/gdb-10.2/gdbserver/remote-utils.cc:1235: undefined reference to `using_threads'
/usr/bin/ld: server.o: in function `main':
/builddir/gdb-10.2/gdbserver/server.cc:3826: undefined reference to `initialize_low()'
...
```

I don't think that gdbserver makes sense for avr and arm-none-eabi.