create a sensible comparison trait hierarchy

* `Ord` inherits from `Eq`
* `TotalOrd` inherits from `TotalEq`
* `TotalOrd` inherits from `Ord`
* `TotalEq` inherits from `Eq`

This is a partial implementation of #12517.

src/test/bench/shootout-k-nucleotide.rs

@@ -26,7 +26,7 @@ static OCCURRENCES: [&'static str, ..5] = [
 
 // Code implementation
 
-#[deriving(Eq, TotalOrd, TotalEq)]
+#[deriving(Eq, Ord, TotalOrd, TotalEq)]
 struct Code(u64);
 
 impl Code {

src/test/compile-fail/deriving-span-Ord-enum-struct-variant.rs

@@ -13,10 +13,10 @@
 #[feature(struct_variant)];
 extern crate extra;
 
-
+#[deriving(Eq)]
 struct Error;
 
-#[deriving(Ord)]
+#[deriving(Eq, Ord)]
 enum Enum {
    A {
      x: Error //~ ERROR

src/test/compile-fail/deriving-span-Ord-enum.rs

@@ -13,10 +13,10 @@
 #[feature(struct_variant)];
 extern crate extra;
 
-
+#[deriving(Eq)]
 struct Error;
 
-#[deriving(Ord)]
+#[deriving(Eq, Ord)]
 enum Enum {
    A(
      Error //~ ERROR

src/test/compile-fail/deriving-span-Ord-struct.rs

@@ -13,10 +13,10 @@
 #[feature(struct_variant)];
 extern crate extra;
 
-
+#[deriving(Eq)]
 struct Error;
 
-#[deriving(Ord)]
+#[deriving(Eq, Ord)]
 struct Struct {
     x: Error //~ ERROR
 //~^ ERROR

src/test/compile-fail/deriving-span-Ord-tuple-struct.rs

@@ -13,10 +13,10 @@
 #[feature(struct_variant)];
 extern crate extra;
 
-
+#[deriving(Eq)]
 struct Error;
 
-#[deriving(Ord)]
+#[deriving(Eq, Ord)]
 struct Struct(
     Error //~ ERROR
 //~^ ERROR

src/test/compile-fail/deriving-span-TotalEq-enum-struct-variant.rs

@@ -13,10 +13,10 @@
 #[feature(struct_variant)];
 extern crate extra;
 
-
+#[deriving(Eq)]
 struct Error;
 
-#[deriving(TotalEq)]
+#[deriving(Eq, TotalEq)]
 enum Enum {
    A {
      x: Error //~ ERROR

src/test/compile-fail/deriving-span-TotalEq-enum.rs

@@ -13,10 +13,10 @@
 #[feature(struct_variant)];
 extern crate extra;
 
-
+#[deriving(Eq)]
 struct Error;
 
-#[deriving(TotalEq)]
+#[deriving(Eq, TotalEq)]
 enum Enum {
    A(
      Error //~ ERROR

src/test/compile-fail/deriving-span-TotalEq-struct.rs

@@ -13,10 +13,10 @@
 #[feature(struct_variant)];
 extern crate extra;
 
-
+#[deriving(Eq)]
 struct Error;
 
-#[deriving(TotalEq)]
+#[deriving(Eq, TotalEq)]
 struct Struct {
     x: Error //~ ERROR
 }

src/test/compile-fail/deriving-span-TotalEq-tuple-struct.rs

@@ -13,10 +13,10 @@
 #[feature(struct_variant)];
 extern crate extra;
 
-
+#[deriving(Eq)]
 struct Error;
 
-#[deriving(TotalEq)]
+#[deriving(Eq, TotalEq)]
 struct Struct(
     Error //~ ERROR
 );

src/test/compile-fail/deriving-span-TotalOrd-enum-struct-variant.rs

@@ -13,10 +13,10 @@
 #[feature(struct_variant)];
 extern crate extra;
 
-#[deriving(TotalEq)]
+#[deriving(Eq, Ord, TotalEq)]
 struct Error;
 
-#[deriving(TotalOrd,TotalEq)]
+#[deriving(Eq, Ord, TotalOrd,TotalEq)]
 enum Enum {
    A {
      x: Error //~ ERROR

src/test/compile-fail/deriving-span-TotalOrd-enum.rs

@@ -13,10 +13,10 @@
 #[feature(struct_variant)];
 extern crate extra;
 
-#[deriving(TotalEq)]
+#[deriving(Eq, Ord, TotalEq)]
 struct Error;
 
-#[deriving(TotalOrd,TotalEq)]
+#[deriving(Eq, Ord, TotalOrd,TotalEq)]
 enum Enum {
    A(
      Error //~ ERROR

src/test/compile-fail/deriving-span-TotalOrd-struct.rs

@@ -13,10 +13,10 @@
 #[feature(struct_variant)];
 extern crate extra;
 
-#[deriving(TotalEq)]
+#[deriving(Eq, Ord, TotalEq)]
 struct Error;
 
-#[deriving(TotalOrd,TotalEq)]
+#[deriving(Eq, Ord, TotalOrd,TotalEq)]
 struct Struct {
     x: Error //~ ERROR
 }

src/test/compile-fail/deriving-span-TotalOrd-tuple-struct.rs

@@ -13,10 +13,10 @@
 #[feature(struct_variant)];
 extern crate extra;
 
-#[deriving(TotalEq)]
+#[deriving(Eq, Ord, TotalEq)]
 struct Error;
 
-#[deriving(TotalOrd,TotalEq)]
+#[deriving(Eq, Ord, TotalOrd,TotalEq)]
 struct Struct(
     Error //~ ERROR
 );

src/test/compile-fail/issue-3344.rs

@@ -8,6 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#[deriving(Eq)]
 struct thing(uint);
 impl Ord for thing { //~ ERROR not all trait methods implemented, missing: `lt`
     fn le(&self, other: &thing) -> bool { true }

src/test/run-pass/cmp-default.rs

@@ -22,6 +22,14 @@ impl Eq for Fool {
 
 struct Int(int);
 
+impl Eq for Int {
+    fn eq(&self, other: &Int) -> bool {
+        let Int(this) = *self;
+        let Int(other) = *other;
+        this == other
+    }
+}
+
 impl Ord for Int {
     fn lt(&self, other: &Int) -> bool {
         let Int(this) = *self;
@@ -32,6 +40,14 @@ impl Ord for Int {
 
 struct RevInt(int);
 
+impl Eq for RevInt {
+    fn eq(&self, other: &RevInt) -> bool {
+        let RevInt(this) = *self;
+        let RevInt(other) = *other;
+        this == other
+    }
+}
+
 impl Ord for RevInt {
     fn lt(&self, other: &RevInt) -> bool {
         let RevInt(this) = *self;

src/test/run-pass/vector-sort-failure-safe.rs

@@ -15,7 +15,7 @@ static MAX_LEN: uint = 20;
 static mut drop_counts: [uint, .. MAX_LEN] = [0, .. MAX_LEN];
 static mut clone_count: uint = 0;
 
-#[deriving(Rand, Ord, TotalEq, TotalOrd)]
+#[deriving(Rand, Eq, Ord, TotalEq, TotalOrd)]
 struct DropCounter { x: uint, clone_num: uint }
 
 impl Clone for DropCounter {