refactor: Devide lib.rs into modules

src/sys.rs

@@ -1,22 +1,30 @@
 #[link(name = "syscalls")]
 extern "C" {
-    #[link_name = "_start_window_draw"]
-    pub fn start_window_draw();
-
-    #[link_name = "_end_window_draw"]
-    pub fn end_window_draw();
-
+    // -1
     #[link_name = "_exit"]
     pub fn exit() -> !;
 
+    // 0
     #[link_name = "_define_window"]
     pub fn define_window(ebx: u32, ecx: u32, edx: u32, esi: u32, edi: u32);
-    #[link_name = "_display_message"]
-    pub fn display_message(ebx: u32, ecx: u32, edx: u32, esi: u32, edi: u32);
 
+    // 2
+    #[link_name = "_pressed_key"]
+    pub fn pressed_key() -> u32;
+
+    // 4
+    #[link_name = "_display_message"]
+    pub fn display_message(ebx: u32, ecx: u32, edx: u32, edi: u32);
+
+    // 10
     #[link_name = "_wait_event"]
     pub fn wait_event() -> u32;
 
-    #[link_name = "_pressed_key"]
-    pub fn pressed_key() -> u32;
+    // 12.1
+    #[link_name = "_start_window_draw"]
+    pub fn start_window_draw();
+
+    // 12.2
+    #[link_name = "_end_window_draw"]
+    pub fn end_window_draw();
 }