These cover the parts of fnmatch() that I think I understand. Missing
FNM_LEADING_DIR because I still haven't understood that yet. All the
descriptions of its behavior that I've seen are slightly (or very)
inconsistent, and it seems like the implementations are genuinely
different too.
Test: treehugger
Change-Id: I1284c406639bef1bfe74db3cad45965c8ab29c2b