Instrument pre-ES6 classes

[dividedmind]

Before ES6 introduced classes class-oriented programming was often implemented in ES (whether by developers or transpilers) by using prototypes directly, for example:

function Person(name) {
  this.name = name;
}

Person.prototype.sayHello = function() {
  console.log("Hello, my name is " + this.name);
}

new Person("Joe").sayHello();

This pattern is not currently instrumented by appmap-node, but can often be present in legacy code. Instrumenting this pattern will make appmap-node more useful in this scenario.