Proposal for enabling shorthand notation for object literal properties

[mhegazy]

This allows ES6 shorthand object literal property definition. This addresses #418. e.g.:

var  a;
var x = { a }; // equivalent to {a : a }

Notes:

• Only identifiers are allowed, keywords are disallows { var }
• Qualified names are not allowed { a.b }
• Any rewriting that would normally happen on the initializer should still occur. e.g.

module m {
    export var x;
}
module m {
   var y = { x }; // should emit { x : m.x }
}

[CyrusNajmabadi]

This seems highly undesirable. We now have a tree that has multiple tokens in it that have the exact same data (i.e. same position/width/etc.)

These trees break rules and lead to funky situations. For example, will the token show up multiple times when getting the children in the services layer? What should features like the formatter do here? Will formatting {a} end up with {a:a}?

We should ahve a new node that represents this type of property assignment.

Or, just dn't have an initializer.

[mhegazy]

Fair. I was lazy. Will fix it.

[JsonFreeman]

Fix indentation

[CyrusNajmabadi]

If we start taking on ES6 features, should we also add a ES6 as an acceptable target version? In ES6 emit mode these would stay as { a } while in ES5/ES3 emit it would be { a: a }

[mhegazy]

When we have an ES6 target we would emit the short hand. In ES3/ES5 we would emit the equivalent long form.