Disable collection of profiling info until a portable library can be used

This slot doesn't really do what it's says it does (redefining it
doesn't change things the way you'd expect) and it causes no end of
headaches by confusing compile-time definitions with run-time
definitions.

Initial import of FiveAM code. This is exactly equal to to bese-2004@common-lisp.net/FiveAM--dev--1.2--patch-20