Rollup test fixes and rebase conflicts

src/libstd/sync/condvar.rs

@@ -307,7 +307,7 @@ mod tests {
         static C: StaticCondvar = CONDVAR_INIT;
         static M: StaticMutex = MUTEX_INIT;
 
-        let mut g = M.lock().unwrap();
+        let g = M.lock().unwrap();
         let _t = Thread::spawn(move|| {
             let _g = M.lock().unwrap();
             C.notify_one();
@@ -386,6 +386,6 @@ mod tests {
         g = C.wait(g).unwrap();
         drop(g);
 
-        C.wait(M2.lock().unwrap()).unwrap();
+        let _ = C.wait(M2.lock().unwrap()).unwrap();
     }
 }

src/libstd/sync/mpsc/select.rs

@@ -337,7 +337,6 @@ mod test {
     use prelude::v1::*;
 
     use thread::Thread;
-    use super::*;
     use sync::mpsc::*;
 
     // Don't use the libstd version so we can pull in the right Select structure

src/libstd/sync/mutex.rs

@@ -447,7 +447,7 @@ mod test {
     fn test_mutex_arc_poison() {
         let arc = Arc::new(Mutex::new(1i));
         let arc2 = arc.clone();
-        Thread::spawn(move|| {
+        let _ = Thread::spawn(move|| {
             let lock = arc2.lock().unwrap();
             assert_eq!(*lock, 2);
         }).join();