Restore Num trait

This restores the trait that was lost in 216e85fadf. It will eventually be broken up into a more fine-grained trait hierarchy in the future once a design can be agreed upon.

src/test/run-pass/trait-inheritance-num.rs

@@ -16,7 +16,7 @@ use core::cmp::{Eq, Ord};
 use core::num::NumCast::from;
 use std::cmp::FuzzyEq;
 
-pub trait NumExt: NumCast + Eq + Ord {}
+pub trait NumExt: Num + NumCast + Eq + Ord {}
 
 pub trait FloatExt: NumExt + FuzzyEq<Self> {}
 

src/test/run-pass/trait-inheritance-num1.rs

@@ -11,7 +11,7 @@
 use core::cmp::Ord;
 use core::num::NumCast::from;
 
-pub trait NumExt: NumCast + Ord { }
+pub trait NumExt: Num + NumCast + Ord { }
 
 fn greater_than_one<T:NumExt>(n: &T) -> bool {
     *n > from(1)

src/test/run-pass/trait-inheritance-num2.rs

@@ -38,7 +38,7 @@ impl TypeExt for f64 {}
 impl TypeExt for float {}
 
 
-pub trait NumExt: TypeExt + Eq + Ord + NumCast {}
+pub trait NumExt: TypeExt + Eq + Ord + Num + NumCast {}
 
 impl NumExt for u8 {}
 impl NumExt for u16 {}

src/test/run-pass/trait-inheritance-num3.rs

@@ -11,7 +11,7 @@
 use core::cmp::{Eq, Ord};
 use core::num::NumCast::from;
 
-pub trait NumExt: Eq + Ord + NumCast {}
+pub trait NumExt: Eq + Ord + Num + NumCast {}
 
 impl NumExt for f32 {}
 

src/test/run-pass/trait-inheritance-num5.rs

@@ -11,7 +11,7 @@
 use core::cmp::{Eq, Ord};
 use core::num::NumCast::from;
 
-pub trait NumExt: Eq + NumCast {}
+pub trait NumExt: Eq + Num + NumCast {}
 
 impl NumExt for f32 {}
 impl NumExt for int {}