[Bug preprocessor/80005] cpp expands __has_include() filename parts

[nathan at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80005

Nathan Sidwell <nathan at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |ASSIGNED
         Resolution|FIXED                       |---

--- Comment #6 from Nathan Sidwell <nathan at gcc dot gnu.org> ---
Reopening.  Sadly my fear turned out to be true.  real code out there presumes
__has_include__ (with the trailing underbars) is how to get at this feature.  
I'm looking at you glibc!

Adding backwards compatibility ...