Doing an abort for invalid va_arg type

[Corey Minyard]

I'm working on a situation where the compiler is producing an
abort when passing a "char" into va_arg.

I know that the code is invalid, but this involves legacy systems.
I would think it better to produce an error in this case, on the
principle that bugs are cheaper to fix the sooner you find them.
Then you could add a flag to allow the "bug" and be ANSI
conformant.  Maybe you could use the '-ansi' flag?

If that isn't acceptable, what about adding a flag to cause an
error any time the compiler would produce an abort?

I'm willing to do a patch either way.

Thanks,

-Corey