This difference is flaky, 1 out of 3.

# Minimized test case:
if (this.Worker) {
  var a = `var b = new Worker('postMessage(42)');
     onmessage = function(parentMsg) {
       b.postMessage(parentMsg);
     };
  `;
  var b = new Worker(a);
  b.postMessage(9);
}

# Compared default with noturbo

# Flags of default:
--abort_on_stack_overflow --expose-gc --allow-natives-syntax --invoke-weak-callbacks --omit-quit --gc-interval=213 --random-seed -495505791
# Flags of noturbo:
--abort_on_stack_overflow --expose-gc --allow-natives-syntax --invoke-weak-callbacks --omit-quit --gc-interval=213 --random-seed -495505791 --turbo-filter=~

Difference:
Different total output lines: 0 vs. 1

### Start of configuration default:

### End of configuration default

### Start of configuration noturbo:
unnamed:87: Uncaught Worker is defunct because main thread is terminating

### End of configuration noturbo