r214722 - Highlight the offending function parameter when the format_arg argument refers to an invalid function parameter type.

[Aaron Ballman]

On Mon, Aug 4, 2014 at 12:34 PM, David Blaikie <dblaikie at gmail.com> wrote:
> Test case? (I know we don't rigorously test the ranges specified in a
> diagnostic, but if we're fixing a bug in it, it might be worthwhile -
> I think they're sometimes tested with the machine readable diagnostic
> format)

I asked about this last week, but there was no conclusion on whether
this sort of change needs tests or how to effectively test it. Can you
point me to a testcase to model after?

~Aaron