[PATCH libICE] Enable visibility annotations

[Alan Coopersmith]

> _IceTransNoListen

While that's absolutely not part of the public API, and no one should have
ever called it, since we utterly failed to give them any way to provide a
reasonable security mode without it, I believe there are several important
callers in the various DE's.

-- 
	-Alan Coopersmith-              alan.coopersmith at oracle.com
	 Oracle Solaris Engineering - http://blogs.oracle.com/alanc