worker: exit after uncaught exception

Previously even after uncaught exception the worker would continue to
execute until there is no more work to do.

lib/internal/worker.js

@@ -467,6 +467,8 @@ function setupChild(evalScript) {
       else
         port.postMessage({ type: messageTypes.COULD_NOT_SERIALIZE_ERROR });
       clearAsyncIdStack();
+
+      process.exit();
     }
   }
 }

test/parallel/test-worker-uncaught-exception-async.js

@@ -10,13 +10,27 @@ if (!process.env.HAS_STARTED_WORKER) {
   const w = new Worker(__filename);
   w.on('message', common.mustNotCall());
   w.on('error', common.mustCall((err) => {
+    console.log(err.message);
     assert(/^Error: foo$/.test(err));
   }));
   w.on('exit', common.mustCall((code) => {
     // uncaughtException is code 1
     assert.strictEqual(code, 1);
   }));
 } else {
+  // cannot use common.mustCall as it cannot catch this
+  let called = false;
+  process.on('exit', (code) => {
+    if (!called) {
+      called = true;
+    } else {
+      assert.fail('Exit callback called twice in worker');
+    }
+  });
+
+  setTimeout(() => assert.fail('Timeout executed after uncaughtException'),
+             2000);
+
   setImmediate(() => {
     throw new Error('foo');
   });

test/parallel/test-worker-uncaught-exception.js

@@ -27,5 +27,9 @@ if (!process.env.HAS_STARTED_WORKER) {
       assert.fail('Exit callback called twice in worker');
     }
   });
+
+  setTimeout(() => assert.fail('Timeout executed after uncaughtException'),
+             2000);
+
   throw new Error('foo');
 }