[PATCH] sim/mcore/interp.c: Include "unistd.h" standard C header file to avoid compiling warnings.

[Joel Brobecker]

> > 2015-02-07  Chen Gang <gang.chen.5i5j@gmail.com>
> > 
> >         * interp.c: Include "unistd.h".
> 
> OK, thanks. I guess, before "git push", I need send patch v2 to mailing
> list.
> 
> If no any additional reply, I shall send patch v2 within 2015-02-10.

The patch was approved and I had no comments on it, so no need to send
v2; just push.

-- 
Joel