[PATCH 1/3] Do not use __builtin_types_compatible_p in C++ mode (bug 21930)

[Gabriel F. T. Gomes]

On Tue, 15 Aug 2017 19:56:44 +0000
Joseph Myers <joseph@codesourcery.com> wrote:

> On Tue, 15 Aug 2017, Gabriel F. T. Gomes wrote:
> 
> > The logic to define isinf for float128 depends on the availability of
> > __builtin_types_compatible_p, which is only available in C mode,
> > however, the conditionals do not check for C or C++ mode.  This lead to
> > an error in libstdc++ configure, as reported by bug 21930.
> > 
> > This patch adds a conditional for C mode in the definition of isinf for
> > float128.  No definition is provided in C++ mode, since libstdc++
> > headers undefine isinf.  
> 
> OK.
> 

Thanks.  I pushed patches 1 and 3 in this thread.  Patch 2 still needs
more changes.