Add proposal for object-nullish-coalescing

[bertyhell]

Proposal for Object property nullish coalescing operator

This proposal shows a new syntax for assigning properties to an object literal but only if the object is not falsy/null or undefined.

Short example:

const myPersonObj = {
    firstName: person.name,
    work?: person.occupation,   // Only set work if person.occupation is truthy, by using the "?:" operator
    street??: person.address    // Only set street is person.address is not null and not undefined, by using the "??:" operator
};

[ljharb]

Proposals can only be added by TC39 members; please see https://github.com/tc39/ecma262/blob/HEAD/CONTRIBUTING.md#new-feature-proposals for more information.

[bertyhell]

ok, i made a discussion topic here: https://es.discourse.group/t/object-nullish-coalescing-operator/1564