clang shorten-64-to-32 warning in qmlcachegen code

signals:
     void captureAndScanFinished(const QVariantList &items); 

onCaptureAndScanFinished: function(items) {
     console.log("scanned", items.length)
}

...
QVariantList r6_0 = (*static_cast<QVariantList*>(argumentsPtr[0]));
QString r11_0;
QVariantList r2_1;
QString r2_0;
QString r12_0;
// generate_LoadRuntimeString
r2_0 = QStringLiteral("scanned");
// generate_StoreReg
r11_0 = std::move(r2_0);
// generate_LoadReg
r2_1 = std::move(r6_0);
// generate_GetLookup
{
int retrieved;
retrieved = r2_1.length();   //!!!!!!!!!!!!!! HERE, LINE 1697
r2_0 = QJSPrimitiveValue(retrieved).toString();
}
...

.../.rcc/qmlcache/mobile_module_ItemScannerDialog_qml.cpp:1697:18: error: implicit conversion loses integer precision: 'qsizetype' (aka 'long long') to 'int' [-Werror,-Wshorten-64-to-32]
retrieved = r2_1.length();
          ~ ~~~~~^~~~~~~~