Use bitflags to create an EntryFlags type

src/memory/paging/entry.rs

@@ -10,4 +10,23 @@ impl Entry {
     pub fn set_unused(&mut self) {
         self.0 = 0;
     }
+
+    pub fn flags(&self) -> EntryFlags {
+        EntryFlags::from_bits_truncate(self.0)
+    }
+}
+
+bitflags! {
+    pub flags EntryFlags: u64 {
+        const PRESENT =         1 << 0,
+        const WRITABLE =        1 << 1,
+        const USER_ACCESSIBLE = 1 << 2,
+        const WRITE_THROUGH =   1 << 3,
+        const NO_CACHE =        1 << 4,
+        const ACCESSED =        1 << 5,
+        const DIRTY =           1 << 6,
+        const HUGE_PAGE =       1 << 7,
+        const GLOBAL =          1 << 8,
+        const NO_EXECUTE =      1 << 63,
+    }
 }