clang+libc++ using missing powl

[Steve Kargl]

On Thu, Sep 05, 2013 at 09:52:13AM +0100, David Chisnall wrote:
> On 4 Sep 2013, at 23:38, Baptiste Daroussin <bapt at freebsd.org> wrote:
> 
> > As a result we have a lot of fallouts of ports complaining about:
> > undefined reference to `powl'
> > 
> > It seems like libc++ is relying on a function we don't have yet
> > in libm, am I missing something?
> 
> I've attached a diff that I'd like to commit to msun

Why not disable libc++ from exposing these functions?

-- 
Steve