RFC: gfc_internal_warning

[Thomas Koenig]

Hello world,

I am currently working on PR 78826, to make sure that everything
in our AST has a location.

Once that is the case, I plan to submit a version of the patch I use
to detect the issue for trunk. Basically, it uses the expression walker
to walk across the whole AST and complain if there is an issue.  This
would catch the case of somebody putting in a new piece of code and
forgetting to update the location information (which is easy to do,
because there currently is no immediate feedback from the compiler).

Question: What short of complaint should it make?  Code generation
is not affected by lack of location information, so a warning would
be more appropriate. The warning would also make sure there are
testsuite failures for any new, wrong code, and users would not
be affected as they would be with an ICE.

I therefore propose to use a new function, gfc_internal_warning, for
this kind of thing.

comments?

	Thomas