assert.throws calls ErrorConstructor before calling fn

[lorenzogrv]

Steps to reproduce:

> cat chai_issue.js
var assert = require('chai').assert;

function FakeErrorConstructor(){
  console.log("constructor executed");
}

assert.throws(function(){
  console.log("before");
  throw new FakeErrorConstructor();
}, FakeErrorConstructor);
> node chai_issue.js

Current output:

constructor executed
before
constructor executed

Expected output:

before
constructor executed