Ignore a deque test on windows

I've seen this fail on windows twice now, and it's not clear to me why it's
failing. For now, ignore it on that platform while investigation enuses.

src/libstd/rt/deque.rs

@@ -590,6 +590,7 @@ mod tests {
     }
 
     #[test]
+    #[ignore(cfg(windows))] // apparently windows scheduling is weird?
     fn no_starvation() {
         static AMT: int = 10000;
         static NTHREADS: int = 4;