Go API Version Documentation

@christophberger I believe it’s not XY Problem, due to the nature that others langs are doing it also without a problem (self opinion).

In long term, Go will add more functions / deprecations, currently the list is maintained in here go/api at master · golang/go · GitHub

However, as the list getting bigger, you probably need to add Go version in function comment doc for 2 reasons:

  1. Make your intention clear toward function changes, and track history.
  2. Easy to look up and pretty straightforward when you browse code.