Permute non-option arguments after --

[wangp]

For GNU compatibility, ya_getopt may want to permute non-option arguments to after "--", e.g.

$ ./test1.ya foo bar -- -x -y
foo bar -- -x -y

vs.

$ ./test1.gnu foo bar -- -x -y
-- foo bar -x -y

Here is the test program:

#include <stdio.h>
#ifdef YA
#include "../ya_getopt.h"
#else
#include <getopt.h>
#endif

int main(int argc, char **argv)
{
    char *optstring = "ab:";
    int opt;
    int i;

    while ((opt = getopt(argc, argv, optstring)) != -1) {
    }
    for (i = 1; i < argc; i++) {
        printf("%s ", argv[i]);
    }
    printf("\n");
    return 0;
}