Re: [TESTING]: ClangBSD branch needs testing before the import to HEAD

I'm just catching up with this thread, so apologies if this has already
been pointed out elsewhere.

One of the things that has been discussed w/rt compilers for a while
(not just at the devsummit) was bending our minds around separating the
concept of "base system compiler" from "default ports compiler".  In
-stable branches, we must and shall not do large compiler updates.  But
ports probably need a more recent compiler (of whatever flavor) just to
keep as many of them building as possible.  (As upstream authors switch
to newer compilers, their ports often don't build on whatever is in our
base).

Despite my enthusiasm for the future of llvm, the reality is that even
in the medium-term there are so many ports with hardwired assumptions
that they are running on gcc (not to mention on linux on i386) that it
will never be possible to fix them all.  The current paradigm is that
as ports stop building with both base gcc, unless they are switched to
depending on a newer gcc from ports, they'll be marked 'broken' and go
through the deprecation cycle.

Further, I remind people that "compile" and "run" and "run equally as
well through all code-paths" are three completely separate levels of
effort, possibly having an order of magnitude more work between each.
We're looking at a multi-year process here, and not every single port is
going to survive.  But again -- not all of them currently do, anwyays.

mcl