add traceur test suite

test/fixtures/traceur/Destructuring/InitializerObject.js

@@ -0,0 +1,12 @@
+var x, z;
+
+({x = {y: 1}} = {});
+assert.deepEqual(x, {y: 1});
+
+({x = {y: {z = 2} = {}}} = {});
+assert.equal(z, 2);
+assert.deepEqual(x, {y: {}});
+
+({x = {y: {z = 3} = {z: 4}}} = {});
+assert.equal(z, 4);
+assert.deepEqual(x, {y: {z: 4}});