完成bitmap的static bitmap功能，能够静态声明bitmap (#490)

* 完成bitmap的static bitmap功能，能够静态声明bitmap

kernel/crates/bitmap/src/lib.rs

@@ -0,0 +1,9 @@
+#![no_std]
+#![feature(core_intrinsics)]
+#![allow(incomplete_features)] // for const generics
+#![feature(generic_const_exprs)]
+
+mod bitmap_core;
+mod static_bitmap;
+pub mod traits;
+pub use static_bitmap::StaticBitmap;