Amend compile-fail tests

Author: canndrew

src/test/compile-fail/match-vec-unreachable.rs

@@ -10,13 +10,14 @@
 
 #![feature(slice_patterns)]
 #![deny(unreachable_patterns)]
+#![allow(unused_variables)]
 
 fn main() {
     let x: Vec<(isize, isize)> = Vec::new();
     let x: &[(isize, isize)] = &x;
     match *x {
-        [_, (2, 3), _] => (),
-        [(1, 2), (2, 3), _] => (), //~ ERROR unreachable pattern
+        [a, (2, 3), _] => (),
+        [(1, 2), (2, 3), b] => (), //~ ERROR unreachable pattern
         _ => ()
     }
 

src/test/compile-fail/unreachable-arm.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:unreachable pattern
-
 #![feature(box_patterns)]
 #![feature(box_syntax)]
 #![allow(dead_code)]
@@ -20,7 +18,7 @@ enum Foo { A(Box<Foo>, isize), B(usize), }
 fn main() {
     match Foo::B(1) {
         Foo::B(_) | Foo::A(box _, 1) => { }
-        Foo::A(_, 1) => { }
+        Foo::A(_, 1) => { } //~ ERROR unreachable pattern
         _ => { }
     }
 }