Method setThreadQoS

valdi/src/valdi/runtime/JavaScript/JavaScriptRuntime.cpp:426–428

        return;
    }

    // Just in case postInit() was never called
    _initLock.leaveIfNotCompleted();

    // Workers share this runtime's listener (see createWorker); detach them so a worker
    // outliving this runtime does not keep a dangling reference. A worker task holding a