change stage1,stage2,stage2 into not(stage0)

With luck, this will allow rust to compile itself without --cfg flags again...

src/libsyntax/ext/base.rs

@@ -461,9 +461,7 @@ impl <K: Eq + Hash + IterBytes ,V: Copy> MapChain<K,V>{
 
     // ugh: can't get this to compile with mut because of the
     // lack of flow sensitivity.
-    #[cfg(stage1)]
-    #[cfg(stage2)]
-    #[cfg(stage3)]
+    #[cfg(not(stage0))]
     fn get_map<'a>(&'a self) -> &'a HashMap<K,@V> {
         match *self {
             BaseMapChain (~ref map) => map,

src/libsyntax/opt_vec.rs

@@ -68,9 +68,7 @@ impl<T> OptVec<T> {
         }
     }
 
-    #[cfg(stage1)]
-    #[cfg(stage2)]
-    #[cfg(stage3)]
+    #[cfg(not(stage0))]
     fn get<'a>(&'a self, i: uint) -> &'a T {
         match *self {
             Empty => fail!(fmt!("Invalid index %u", i)),