[Bug c++/57699] Disable empty parameter list misinterpretation in libstdc++ headers when !defined(NO_IMPLICIT_EXTERN_C)

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57699

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Bernd Edlinger from comment #3)
> Is this NO_IMPLICIT_EXTERN_C define set by the
> configure script?

It's set by headers under gcc/config/

> Should I make sure that the
> configure script sets NO_IMPLICIT_EXTERN_C?

Yes, but whether eCos defines it is not really relevant to this PR, which is
about the general feature not whether it's used on a given platform or not.