Snippets for msgpack-cxx 7.0.0 from Alpine s390x

Sourced from https://build.alpinelinux.org/buildlogs/build-edge-s390x/community/msgpack-cxx/msgpack-cxx-7.0.0-r1.log.

• /home/buildozer/aports/community/msgpack-cxx/src/msgpack-cxx-7.0.0/include/msgpack/v1/detail/cpp11_zone.hpp:197:15: warning: 'void free(void*)' called on pointer returned from a mismatched allocation function [-Wmismatched-new-delete]
    197 |         ::free(p);
        |         ~~~~~~^~~