strsignal prototype disabled on all but Cygwin

[Ralf Corsepius]

On 01/07/2011 09:32 PM, Joel Sherrill wrote:
> Hi,
>
> The strsignal() prototype is not defined unless you
> are on Cygwin. Since this is provided by newlib,
> I think the ifdef is wrong. The attached ifdef enables
> it for RTEMS.
>
> But I suspect it should be enabled for more.

According to OpenGroup strsignal is a CX extension (POSIX extension to 
ISO C).

I am inclined to think it should be provided unconditionally.

Ralf