I'm not a plan 9 programmer, but to me it looks 'cute' (in the sense of attractive to some people but annoying to others) - that form of abort() would only be used on systems where that operation is known to abort the process, but enclosing it in a while simply makes it apparent that there is no alternative to trying it.

On a more prosaic note, perhaps

    for(;;)
        *(int *)0;

generates a compiler warning that the programmer wanted to avoid.