Update the big examples too

book/games/pong/src/main.rs

@@ -33,9 +33,7 @@ mod gfx {
 // ensures that everything is in order. `agb` will call this after setting up the stack
 // and interrupt handlers correctly.
 #[agb::entry]
-fn main() -> ! {
-    let mut gba = Gba::new();
-
+fn main(mut gba: Gba) -> ! {
     let _tiled = gba.display.video.tiled0();
     let mut object = gba.display.object.get();
     gfx::load_sprite_data(&mut object);

examples/the-hat-chooses-the-wizard/src/main.rs

@@ -772,10 +772,8 @@ impl<'a, 'b, 'c> PlayingLevel<'a, 'b> {
     }
 }
 
-#[no_mangle]
-pub fn main() -> ! {
-    let mut agb = agb::Gba::new();
-
+#[agb::entry]
+fn main(mut agb: agb::Gba) -> ! {
     splash_screen::show_splash_screen(&mut agb, splash_screen::SplashScreen::Start, None, None);
 
     loop {

examples/the-purple-night/src/main.rs

@@ -2207,9 +2207,7 @@ mod tilemap {
 }
 
 #[agb::entry]
-fn main() -> ! {
-    let mut gba = agb::Gba::new();
-
+fn main(mut gba: agb::Gba) -> ! {
     loop {
         game_with_level(&mut gba);
     }