rustc: Add an "ne" method to the Eq trait, and implement it everywhere

src/test/run-pass/expr-if-struct.rs

@@ -14,6 +14,7 @@ impl mood : cmp::Eq {
     pure fn eq(&&other: mood) -> bool {
         (self as uint) == (other as uint)
     }
+    pure fn ne(&&other: mood) -> bool { !self.eq(other) }
 }
 
 fn test_tag() {