feat: benchmark App::update()

benches/app/app.rs

@@ -0,0 +1,16 @@
+use bevy::app::prelude::*;
+use criterion::Criterion;
+
+pub fn update(c: &mut Criterion) {
+    let mut group = c.benchmark_group("app::app::update");
+
+    group.bench_function("empty", |b| {
+        let mut app = App::empty();
+        b.iter(|| app.update());
+    });
+
+    group.bench_function("new", |b| {
+        let mut app = App::new();
+        b.iter(|| app.update());
+    });
+}

benches/app/mod.rs

@@ -0,0 +1,5 @@
+mod app;
+
+use criterion::criterion_group;
+
+criterion_group!(group, app::update,);

benches/main.rs

@@ -1,3 +1,4 @@
+mod app;
 mod ecs;
 
 use criterion::criterion_main;
@@ -10,4 +11,4 @@ pub(crate) fn create_prng() -> impl Rng {
     SmallRng::seed_from_u64(0x7df09deb486e920a)
 }
 
-criterion_main!(ecs::group);
+criterion_main!(app::group, ecs::group);