Add bench_typed_arena_clear_100 bench

compiler/rustc_arena/src/tests.rs

@@ -121,6 +121,17 @@ pub fn bench_typed_arena_clear(b: &mut Bencher) {
     })
 }
 
+#[bench]
+pub fn bench_typed_arena_clear_100(b: &mut Bencher) {
+    let mut arena = TypedArena::default();
+    b.iter(|| {
+        for _ in 0..100 {
+            arena.alloc(Point { x: 1, y: 2, z: 3 });
+        }
+        arena.clear();
+    })
+}
+
 // Drop tests
 
 struct DropCounter<'a> {