cmake HAVE_C_MALLOPT examples

netdata/netdata CMakeLists.txt :568

check_c_source_compiles("
#include <malloc.h>
int main() {
        mallopt(M_ARENA_MAX, 1);
        mallopt(M_PERTURB, 0x5A);
        return 0;
}
" HAVE_C_MALLOPT)