Xcode pin menu for adding Auto Layout constraints is missing

In case anyone has this problem: the one piece of information is missing from the otherwise correct answers - these icons are in the lower RIGHT corner. As such, if you don't have your storyboard view wide enough you won't get them - you have to increase the size of the view then you will see them.

At the bottom-right corner of canvas view there are some icons, one of them is the new pin menu. Use it

Pin in storyboard

Verified in Xcode 8.3 Swift 3 There is a possibility that Autolayout was disabled while creating the project. Select Main.storyboard, In the right menu that has "File Inspector", under the section 'Interface Builder Document', enable 'Use Auto Layout'. The pin menu comes up at the usual place - bottom right corner

Select the Storyboard file in the navigator, open the utilities menu on the top right, show the file inspector (the left icon) and under the Interface Builder Document menu, click Use Auto Layout.

Regards