[9fans] Don't Plan 9 C compiler initialize the rest of member of a struct?

[Kyohei Kadota]

Hi, 9fans. I use 9legacy.

About below program, I expected that flags field will initialize to
zero but the value of flags was a garbage, ex, "f8f7".
Is this expected?

```
#include <stdio.h>

struct option {
    int n;
    char *s;
    int flags;
};

int
main(void)
{
    struct option opt = {1, "test"};
    printf("%d %s %x\n", opt.n, opt.s, opt.flags);
    return 0;
}
```