std: remove the equals method from TotalEq.

`TotalEq` is now just an assertion about the `Eq` impl of a
type (i.e. `==` is a total equality if a type implements `TotalEq`) so
the extra method is just confusing.

Also, a new method magically appeared as a hack to allow deriving to
assert that the contents of a struct/enum are also TotalEq, because the
deriving infrastructure makes it very hard to do anything but create a
trait method. (You didn't hear about this horrible work-around from me
:(.)

src/libstd/tuple.rs

@@ -75,12 +75,7 @@ macro_rules! tuple_impls {
             }
 
             #[cfg(not(test))]
-            impl<$($T:TotalEq),+> TotalEq for ($($T,)+) {
-                #[inline]
-                fn equals(&self, other: &($($T,)+)) -> bool {
-                    $(self.$refN().equals(other.$refN()))&&+
-                }
-            }
+            impl<$($T:TotalEq),+> TotalEq for ($($T,)+) {}
 
             #[cfg(not(test))]
             impl<$($T:Ord + Eq),+> Ord for ($($T,)+) {
@@ -338,12 +333,6 @@ mod tests {
         assert!(((1.0, 2.0) < (2.0, nan)));
         assert!(!((2.0, 2.0) < (2.0, nan)));
 
-        // TotalEq
-        assert!(small.equals(&small));
-        assert!(big.equals(&big));
-        assert!(!small.equals(&big));
-        assert!(!big.equals(&small));
-
         // TotalOrd
         assert!(small.cmp(&small) == Equal);
         assert!(big.cmp(&big) == Equal);