cmake LIBC_HAS_ARGP examples

Yoshimi/yoshimi src/CMakeLists.txt :159

check_c_source_compiles (
    "#include <argp.h>
    #include <stdlib.h>
    int main () {
        int argc=1;
        char *argv[]={\"test\"};
        argp_parse(0,argc,argv,0,0,0);
        return 0;
    }" LIBC_HAS_ARGP
)