fixed #11797 (Crash: filename mismatch) - skip missing files in Visual Studio projects
Still needs the test to be adjusted for filesystems which are case insensitive.
This just prevents the crash. Additional handling would be a heuristic to lowercase the filename and check that on case sensitive filesystems.
We also somehow need to propagate the skipping back so the analysis will error out. But we have nothing in place to report such errors during the command-line processing as that requires the settings to exist. But I have an idea about that will file a ticket.
This exposed MacOS filesystem actually being case insensitive. I filed https://github.com/danmar/simplecpp/issues/309 and https://trac.cppcheck.net/ticket/11926 about it.