fails to buid on mips(el): undefined reference to `__sync_fetch_and_add_8'

fastnetmon fails to build on the Debian architectures mips, mipsel, m68k, powerpc, sh4:

```

/usr/bin/c++  -g -O2 -fdebug-prefix-map=/<<BUILDDIR>>/fastnetmon-1.1.3+dfsg=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2  -Wl,-z,relro -Wl,-z,now -rdynamic CMakeFiles/fastnetmon.dir/fastnetmon.cpp.o  -o fastnetmon -lboost_thread -lboost_regex -lboost_program_options -lboost_system -lboost_chrono -lboost_date_time -lboost_atomic -lpthread -lhiredis -lmongoc-1.0 -lbson-1.0 libfast_dpi.a -llog4cpp -lpthread libpatricia.a libfastnetmon_pcap_format.a libipfix_rfc.a libfast_library.a libunified_parser.a libafpacket_plugin.a libsflow_plugin.a libnetflow_plugin.a libpcap_plugin.a libexample_plugin.a libnetmap_plugin.a -lndpi -lboost_thread -lboost_regex -lboost_program_options -lboost_system -lboost_chrono -lboost_date_time -lboost_atomic -lpthread libpatricia.a libfastnetmon_pcap_format.a -ljson-c libunified_parser.a libipfix_rfc.a -lluajit-5.1 -lpcap libfastnetmon_packet_parser.a 

CMakeFiles/fastnetmon.dir/fastnetmon.cpp.o: In function `process_packet(simple_packet&)':

./obj-mipsel-linux-gnu/./src/fastnetmon.cpp:1698: undefined reference to `__sync_fetch_and_add_8'

./obj-mipsel-linux-gnu/./src/fastnetmon.cpp:1788: undefined reference to `__sync_fetch_and_add_8'

./obj-mipsel-linux-gnu/./src/fastnetmon.cpp:1789: undefined reference to `__sync_fetch_and_add_8'

./obj-mipsel-linux-gnu/./src/fastnetmon.cpp:1788: undefined reference to `__sync_fetch_and_add_8'

./obj-mipsel-linux-gnu/./src/fastnetmon.cpp:1789: undefined reference to `__sync_fetch_and_add_8'

CMakeFiles/fastnetmon.dir/fastnetmon.cpp.o:./obj-mipsel-linux-gnu/./src/fastnetmon.cpp:1916: more undefined references to `__sync_fetch_and_add_8' follow

collect2: error: ld returned 1 exit status

CMakeFiles/fastnetmon.dir/build.make:135: recipe for target 'fastnetmon' failed

make[3]: *** [fastnetmon] Error 1

```



The problem is that these architectures do not provide a 64-bit versions of `__sync_fetch_and_add` (i.e. `__sync_fetch_and_add_8`):

```

bdrung@eller:~$ readelf -a /lib/mipsel-linux-gnu/libgcc_s.so.1 | grep __sync_add_and_fetch

     6: 00011060    36 FUNC    GLOBAL DEFAULT   13 __sync_add_and_fetch_4@@GCC_4.4.0

   108: 00010fa0    88 FUNC    GLOBAL DEFAULT   13 __sync_add_and_fetch_1@@GCC_4.4.0

   696: 00011000    88 FUNC    GLOBAL DEFAULT   13 __sync_add_and_fetch_2@@GCC_4.4.0

```



The atomic library does not provide `__sync_add_and_fetch`.



Debian-Bug: https://bugs.debian.org/869805

[]