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/auto_encode.rs

@@ -98,8 +98,8 @@ use ext::base::*;
 use parse;
 
 use core::vec;
-use std::map;
-use std::map::HashMap;
+use std::oldmap;
+use std::oldmap::HashMap;
 
 // Transitional reexports so qquote can find the paths it is looking for
 mod syntax {