rename map -> oldmap and mark it as deprecated

LinearMap is quite a bit faster, and is fully owned/sendable without
requiring copies. The older std::map also doesn't use explicit self and
relies on mutable fields.

src/libsyntax/ext/base.rs

@@ -20,7 +20,7 @@ use parse::{parser, token};
 
 use core::io;
 use core::vec;
-use std::map::HashMap;
+use std::oldmap::HashMap;
 
 // new-style macro! tt code:
 //