Auto merge of #23512 - oli-obk:result_ok_unwrap, r=alexcrichton

because then the call to `unwrap()` will not print the error object.

src/test/run-pass/spawn2.rs

@@ -12,7 +12,7 @@ use std::thread;
 
 pub fn main() {
     let t = thread::spawn(move|| child((10, 20, 30, 40, 50, 60, 70, 80, 90)) );
-    t.join().ok().unwrap();
+    t.join().ok().unwrap(); // forget Err value, since it doesn't implement Debug
 }
 
 fn child(args: (int, int, int, int, int, int, int, int, int)) {

src/test/run-pass/unit-like-struct-drop-run.rs

@@ -26,6 +26,6 @@ pub fn main() {
         let _b = Foo;
     }).join();
 
-    let s = x.err().unwrap().downcast::<&'static str>().ok().unwrap();
+    let s = x.err().unwrap().downcast::<&'static str>().unwrap();
     assert_eq!(&**s, "This panic should happen.");
 }