DO NOT MERGE

try to debug the aio_suspend test failure on OSX

I suspect there may be a memory layout problem

Author: asomers

src/sys/aio.rs

@@ -985,6 +985,7 @@ pub fn aio_suspend(list: &[&AioCb], timeout: Option<TimeSpec>) -> Result<()> {
         Some(x) => x.as_ref() as *const libc::timespec
     };
     Errno::result(unsafe {
+        dbg!((&list[0].aiocb) as *const _, *p.offset(0), (&list[1].aiocb) as *const _, *p.offset(1));
         libc::aio_suspend(p, list.len() as i32, timep)
     }).map(drop)
 }