Description
Since some files in compat/ are pulled externally, ideally we should not update them unless absolutely necessary. As a result, we should find what these files are and blacklist Cocci from being run on them.
One thing to consider, some files are Windows-only and are never Coccinelled whenever we compile on Windows. Do we want to make Cocci run on all files, regardless of whether or not they're compilable on the current platform? Upside is that Szeder found some files that could be patched that we weren't catching. Downside is that there is no way to test the code to ensure that it works properly.
Another stretch goal is to do the extern removal on files that we do own in compat/, since those were explicitly excluded during the big extern cleanup since those were intentionally excluded in b199d71 (.[ch]: remove extern from function declarations using sed, 2019-04-29) and 5545442 (.[ch]: remove extern from function declarations using spatch, 2019-04-29).