[RFA/JVMTI] Fix a couple of thinkos

[Keith Seitz]

Tom Tromey wrote:
> Keith> First, the JVMTI namespace I
> Keith> introduced to jvmti-int.h for event processing must have all the
> Keith> members declared extern (and subsequently defined in one place).
> 
> This part is ok.

Ok, I'm going to commit this since it is going to end up blocking 
submission of my next patch (it would otherwise introduce a build error).

> Keith> +  /* Don't even think about locking the env list here. It will prevent
> Keith> +     any events from being posted if some thread suspended as a result
> Keith> +     of a previous event. */
> 
> We may have to defer manipulations of the env list until it is safe.

I'll work on a better solution and resubmit this portion.

Thanks,
Keith