mm: add basic paging infra from x86_64 crate

the x86_64 crate is pretty solid and has a permissive license
(Apache/MIT), but I want to make this myself in the future to
"experience" the unsafe rust further....Also it has too many
abstractions, which is justified as a library, but not ideal for a from
sctrach toy OS as it hides the lower end.

Signed-off-by: Tianhao Wang <shrik3@mailbox.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 0eb1c7d..8b561ce 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -2,6 +2,7 @@
 #![allow(unused_imports)]
 #![no_std]
 #![no_main]
+#![feature(const_option)]
 mod arch;
 mod defs;
 mod ds;