fix: improve test-worker.js to assert promise results are correct

Also hush some console messages, and test the local worker as well (for
parallelism).

closes Agoric#1778

packages/SwingSet/test/workers/test-worker.js

@@ -23,21 +23,17 @@ test('local vat manager', async t => {
   const c = await makeController('local');
   t.teardown(c.shutdown);
 
-  console.log('@@ready to run...');
   await c.run();
   t.is(c.kpStatus(c.bootstrapResult), 'fulfilled');
   t.deepEqual(c.dump().log, ['testLog works']);
   t.deepEqual(JSON.parse(c.kpResolution(c.bootstrapResult).body), expected);
 });
 
-// The XS worker is disabled until the xsnap-based approach is ready for
-// testing. Unlike the old approach, I think we'll build xsnap
-// unconditionally, so we won't need the old 'maybeTestXS' conditional.
-
 test('xs vat manager', async t => {
   const c = await makeController('xs-worker');
   t.teardown(c.shutdown);
 
+  console.log('@@ready to run...');
   await c.run();
   t.is(c.kpStatus(c.bootstrapResult), 'fulfilled');
   t.deepEqual(c.dump().log, ['testLog works']);