Is it a benefit for companies to hire an employee ready to listen anytime to employees whenever they feel down due to work pressure, stress...?

Do you mean hiring an employee who also serves as a guidance counselor or Mr. Wisdom? If this is the case then yes, it will be good to have an employee who cares for his/her colleagues and shares his/her philosophical views to relieve pressure, stress, and negative thinking. 

First of all this is the job of supervisors to look for the employees output and pressure stress problems rather to go for hiring another person. Because the stress pressure will never release if the supervisor don’t want to decrease the work pressure. So better the manager should make a mechanism in which he come to know the exact situation of workers problems like make a questionnaire and ask the workers to submit the answers  like q1. Are you satisfied from the work timing? q2. Your supervisor is helpful? What you want to change? q4. During work what is your biggest problem? q5. Are you satisfied from the suppliers or materials or inspection method? Overtimes, salary, etc.... many question we can ask and get answers better ask worker don't write his name or number and prepare a result to see which area need to improve.

So I am not agree to hire an extra employee because he has no magic stick to remove all the stress in one minute or one day until the whole supervisors, management staff look the workers current condition in depth. If there is no employee care from the management then how the work will make progress.

Yes definitely.

Well firstly  it is the job of Manager to create friendly behavior with their employees to reduce stress rather than hire positive employees.

if Manager did not then

employees can motivate each other , through employee union.

Well i think it will be bad for the organization ,  

With the answer Mr. Muhammed Qasim

I think every company want that type of person. I think these people strive in all kinds of situations.

The language

YES.