Style fixes

tests/run-pass/reentrant-println.rs

@@ -3,7 +3,7 @@
 // This test case exercises std::sys_common::remutex::ReentrantMutex
 // by calling println!() from inside fmt
 
-struct InterruptingCow();
+struct InterruptingCow;
 
 impl Display for InterruptingCow {
     fn fmt(&self, _f: &mut Formatter<'_>) -> Result<(), Error> {
@@ -13,5 +13,5 @@ fn fmt(&self, _f: &mut Formatter<'_>) -> Result<(), Error> {
 }
 
 fn main() {
-    println!("\"Knock knock\" \"Who's {} there?\"", InterruptingCow());
+    println!("\"Knock knock\" \"Who's {} there?\"", InterruptingCow);
 }

tests/run-pass/sync.rs

@@ -1,5 +1,3 @@
-// Requires full MIR on Windows.
-
 #![feature(rustc_private)]
 
 use std::sync::{Mutex, RwLock, TryLockError};