Add nuke_limited counter(Number of times reached nuke_limit.)

[Dridi Boukelmoune]

On Fri, Feb 16, 2018 at 10:56 AM, kokoniimasu <kokoniimasu at gmail.com> wrote:
> Hi, Dridi.
>
> Thank you for your comment!
> I will create pull-request.

You may want to name the counter n_lru_limited or something similar to
be consistent with related counters.

Cheers