Fix emitted code for variable statement with no bound variables

[DanielRosenwasser]

Fixes #3893.

[mhegazy]

can you also add a test for assignments,

var a: any;

({} = a);
([] = a);

({}) => { };
([]) => { };

[DanielRosenwasser]

I've already written tests for that elsewhere. See

• tests/cases/conformance/es6/destructuring/emptyAssignmentPatterns01_ES5.ts
• tests/cases/conformance/es6/destructuring/emptyObjectBindingPatternParameter01.ts
• tests/cases/conformance/es6/destructuring/emptyArrayBindingPatternParameter01.ts

[JsonFreeman]

Does this work for parameters?

function f({} = {}) { }
function g([] = []) { }

[DanielRosenwasser]

We have tests/cases/conformance/es6/destructuring/emptyObjectBindingPatternParameter04.ts whose baselines seem fine.

[DanielRosenwasser]

Actually @JsonFreeman, since the issue was when an identifier appeared in the initializer, that's what we should be testing. I'll amend my tests.

[DanielRosenwasser]

Done. I've added cases in

• tests/cases/conformance/es6/destructuring/emptyVariableDeclarationBindingPatterns01_ES5.ts
• tests/cases/conformance/es6/destructuring/emptyVariableDeclarationBindingPatterns01_ES6.ts