Fix mcontext_t sigcontext namespace (bug 21457)

[Joseph Myers]

On Tue, 27 Jun 2017, Florian Weimer wrote:

> On 06/27/2017 05:27 PM, Szabolcs Nagy wrote:
> 
> >> For some previous patches in this series, changing stack_t and ucontext_t, 
> >> Florian checked there were no affected mangled names in Fedora, as 
> >> evidence for such problems being rare.  Such a check might be worthwhile 
> >> here (remembering that what is being looked for is architecture-specific, 
> >> but on x86_64 / x86 the mangled name is already mcontext_t and would not 
> >> change because there aren't namespace issues there).
> >>
> > 
> > Florian, if you can check, then please do.
> 
> What's the old mangled name I would have to look for?  sigcontext?

On x86_64 and x86, it's mcontext_t (and won't change).  On AArch64, it's 
sigcontext.

-- 
Joseph S. Myers
joseph@codesourcery.com