auto merge of #12697 : thestinger/rust/vec, r=huonw

This exists for the sake of compatibility during the ~[T] -> Vec<T>
transition. It will be removed in the future.

src/libstd/vec_ng.rs

@@ -369,6 +369,7 @@ impl<T> Vec<T> {
     }
 
     #[inline]
+    #[deprecated="Use `xs.iter().map(closure)` instead."]
     pub fn map<U>(&self, f: |t: &T| -> U) -> Vec<U> {
         self.iter().map(f).collect()
     }