Disable lto on s390x
    
    In function 'strncpy',
        inlined from 'fctstr_safe_cpy' at /builddir/build/BUILD/sems-baad4717fdb3c02a63eb4869f31ec33ff8ec1fed/core/tests/fct.h:267:12,
        inlined from 'fct_ts_new' at /builddir/build/BUILD/sems-baad4717fdb3c02a63eb4869f31ec33ff8ec1fed/core/tests/fct.h:1157:20:
    /usr/include/bits/string_fortified.h:106:34: error: '__builtin_strncpy' specified bound 256 equals destination size [-Werror=stringop-truncation]
      106 |   return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
          |                                  ^
    lto1: some warnings being treated as errors