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_new_proto.js

@@ -0,0 +1,14 @@
+var ITERATIONS = 20000;
+
+function Animal(name) {
+  this.name = name;
+}
+Animal.prototype.getName = function () {
+  return this.name;
+};
+var sum = 0;
+for (var i = 0; i < ITERATIONS; i++) {
+  var a = new Animal("x");
+  sum += a.getName().length;
+}
+sum