Vendor dependencies for 0.3.0 release

vendor/tracing/benches/dispatch_get_clone.rs

@@ -0,0 +1,15 @@
+use criterion::{black_box, criterion_group, criterion_main, Criterion};
+
+mod shared;
+
+fn bench(c: &mut Criterion) {
+    shared::for_all_dispatches(&mut c.benchmark_group("Dispatch::get_clone"), |b| {
+        b.iter(|| {
+            let current = tracing::dispatcher::get_default(|current| current.clone());
+            black_box(current);
+        })
+    });
+}
+
+criterion_group!(benches, bench);
+criterion_main!(benches);