feat: 拆分 stress benchmark 到细粒度单热点测试并修复 bench 采样逻辑

tests/stress/call_closure.js

@@ -0,0 +1,14 @@
+var ITERATIONS = 20000;
+
+function outer() {
+  var x = 1;
+  return function (n) {
+    return x + n;
+  };
+}
+var inner = outer();
+var sum = 0;
+for (var i = 0; i < ITERATIONS; i++) {
+  sum += inner(i);
+}
+sum