The idea of using middleware test suites to test Wine has come up before, I'm sure, but while looking for real world uses of overlapped I/O to named pipes for my named pipe conformance test, I noticed a good candidate.
ACE is a set of object-oriented wrappers around operating system primitives, See http://www.cs.wustl.edu/~schmidt/ACE.html I think it's cruft (hey, it's c++ :-), but in spite of that, it is the basis of a whole lot of software, some very, very good. Ace has a largish set of regression tests which, being tests of a fairly thin OS abstraction layer, would be an almost perfect match for Wine's needs. See http://cvs.doc.wustl.edu/ace-cvs.cgi/ACE_wrappers/tests/README?rev=4.25 for more info about their regression tests.
Can someone with a beefy machine and time on their hands give this a shot under Wine? Presumably you'd build everything with msvc, then run the tests under Wine.
Warning: ACE is huge, and will hurt your head if you're not prepared. Wear sunglasses or something :-) - Dan