[Bug fortran/53934] Better CPP macro diagnostics

[manu at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53934
Bug 53934 depends on bug 53552, which changed state.

Bug 53552 Summary: Add support for !GCC$ warning directive (cf. #pragma warning)
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53552

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |DUPLICATE