Fix ctan, ctanh overflow (bug 11521)

[Ryan S. Arnold]

On Thu, Apr 26, 2012 at 11:03 AM, Ryan S. Arnold <ryan.arnold@gmail.com> wrote:
> Otherwise the patch itself looks good and cleans up the problem.  I'll
> push upstream shortly.

Pushed upstream as git commit commit 0ac229c819afd15ba323838ba72d0a409f16acc4
Author: Adhemerval Zanella <azanella@linux.vnet.ibm.com>
Date:   Thu Apr 26 11:18:11 2012 -0500

    Fix ctan, ctanh overflow for ldbl-128ibm (bug 11521).

Ryan S. Arnold