ping

In the apparent absence of the libquadmath maintainers, could a global reviewer approve this rather simple patch, please?
 


> The attached patch adds logbq() to libquadmath, with code lifted from glibc.
> It is made necessary by an upcoming patch for gfortran, adding full support for the IEEE modules on __float128, and requires logbq().
> 
> Bootstrapped and regtested on x86_64-apple-darwin14.
> OK to commit to trunk?
> 
> FX