Refactor strtod parsing of NaN payloads

[Joseph Myers]

On Tue, 24 Nov 2015, Florian Weimer wrote:

> > The point of this refactoring is so that a future change can call these 
> > (libc) functions from the nan* functions in libm.  I don't think 
> > internal_function is compatible with PLT calls from other libraries.
> 
> internal_function is a bit of a misnomer, it just affects the calling
> convention on some architectures.  Unlike attribute_hidden, it does not
> interfere with linking, as long as the caller uses the same prototype
> (with the internal_function attribute).

But is that calling convention change compatible with calling through the 
PLT?

-- 
Joseph S. Myers
joseph@codesourcery.com