Issue #5656: Make &self not mean "&'self self"

Fixes #5656.
Fixes #5541.

src/libsyntax/ext/base.rs

@@ -454,6 +454,7 @@ 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(stage0)]
     fn get_map(&self) -> &'self HashMap<K,@V> {
         match *self {
             BaseMapChain (~ref map) => map,
@@ -461,6 +462,18 @@ 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)]
+    fn get_map<'a>(&'a self) -> &'a HashMap<K,@V> {
+        match *self {
+            BaseMapChain (~ref map) => map,
+            ConsMapChain (~ref map,_) => map
+        }
+    }
+
 // traits just don't work anywhere...?
 //pub impl Map<Name,SyntaxExtension> for MapChain {