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/parse/common.rs

@@ -18,7 +18,7 @@ use parse::token;
 
 use core::option::{None, Option, Some};
 use core::option;
-use std::map::HashMap;
+use std::oldmap::HashMap;
 
 pub type seq_sep = {
     sep: Option<token::Token>,