Primitive E module for a BUF gate.
We use this to implement vl2014::*vl-1-bit-buf*. This is used for real BUF gates, not for ordinary assignments; see also *esim-id*.
Definition:
(defconst *esim-buf* '(:n *esim-buf* :x (:out ((|out| buf |in|))) :i ((|in|)) :o ((|out|))))