pointer to interface type.
R=golang-dev, niemeyer, gri
CC=golang-dev
https://golang.org/cl/
4173067
<!-- title The Go Programming Language Specification -->
-<!-- subtitle Version of February 15, 2011 -->
+<!-- subtitle Version of February 19, 2011 -->
<!--
TODO
expression is illegal.
</li>
<li>
-For a variable <code>x</code> of type <code>I</code> or <code>*I</code>
+For a variable <code>x</code> of type <code>I</code>
where <code>I</code> is an interface type,
<code>x.f</code> denotes the actual method with name <code>f</code> of the value assigned
to <code>x</code> if there is such a method.