[Bug c/80529] Split "C++ style comments are not allowed in ISO C90" pedwarn into its own warning flag

["manu at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80529

Manuel López-Ibáñez <manu at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |manu at gcc dot gnu.org

--- Comment #7 from Manuel López-Ibáñez <manu at gcc dot gnu.org> ---
(In reply to Jonathan Wakely from comment #3)
> Because I'm not childish and realise that clang-tidy is a better tool than a
> compiler when you want to enforce style guides.

In fact, the effort and time spent on adding more and more warnings about style
would be better spent on creating a gcc-tidy tool. Even adding a flag for an
existing warning has a cost.

Having a gcc-tidy tool would benefit gcc by encouraging abstraction and
modularization, and benefit users by making easier to add any particular style
warnings.