error pedantic: ISO C++ forbids zero-size array

[heri16]

We're getting an error when linking to eixx:

/usr/local/opt/eixx@1.4/include/eixx/marshal/list.hpp:65:30: error: ISO C++ forbids zero-size array 'head' [-Werror=pedantic]
   65 |         cons_t          head[0];
      |                              ^
In file included from /usr/local/opt/eixx@1.4/include/eixx/marshal/eterm_format.hpp:69,
                 from /usr/local/opt/eixx@1.4/include/eixx/marshal/eterm.hxx:36,
                 from /usr/local/opt/eixx@1.4/include/eixx/marshal/eterm.hpp:691,
                 from /usr/local/opt/eixx@1.4/include/eixx/eterm.hpp:33,
                 from /usr/local/opt/eixx@1.4/include/eixx/eixx.hpp:61

[saleyn]

Fixed