wasm: crash on threaded d'tor

While testing QtConcurrent with wasm, I experienced a crash when the d'tor ran in the example app runfunction:

10:05:49.932 Hello "Alice" from QThread(0x8e6940, name = "Thread (pooled)") 2 qtloader.js:382:25
10:05:49.933 Hello "Bob" from QThread(0x8e6b38, name = "Thread (pooled)") qtloader.js:382:25
10:05:49.935 exception thrown: Error: Invalid argument,ErrnoError@http://192.168.1.106:6931/qtloader.js line 443 > eval:4852:60
unmount@http://192.168.1.106:6931/qtloader.js line 443 > eval:4071:17
ASM_CONSTS<@http://192.168.1.106:6931/qtloader.js line 443 > eval:1848:34
_emscripten_asm_const_iii@http://192.168.1.106:6931/qtloader.js line 443 > eval:1881:27
QCoreApplicationPrivate::~QCoreApplicationPrivate()@http://192.168.1.106:6931/runfunction.wasm:wasm-function[36960]:0x64b830
QGuiApplicationPrivate::~QGuiApplicationPrivate()@http://192.168.1.106:6931/runfunction.wasm:wasm-function[11393]:0x3bf5e2
QApplicationPrivate::~QApplicationPrivate()@http://192.168.1.106:6931/runfunction.wasm:wasm-function[2401]:0xf5d78
QApplicationPrivate::~QApplicationPrivate().1@http://192.168.1.106:6931/runfunction.wasm:wasm-function[2402]:0xf5d83
QScopedPointerDeleter<QObjectData>::cleanup(QObjectData*)@http://192.168.1.106:6931/runfunction.wasm:wasm-function[38813]:0x65ee15
QScopedPointer<QObjectData, QScopedPointerDeleter<QObjectData> >::~QScopedPointer()@http://192.168.1.106:6931/runfunction.wasm:wasm-function[38812]:0x65edfb
QObject::~QObject()@http://192.168.1.106:6931/runfunction.wasm:wasm-function[38815]:0x65f1f9
QCoreApplication::~QCoreApplication()@http://192.168.1.106:6931/runfunction.wasm:wasm-function[37002]:0x64c693
QGuiApplication::~QGuiApplication()@http://192.168.1.106:6931/runfunction.wasm:wasm-function[11207]:0x3bcbc6
QApplication::~QApplication()@http://192.168.1.106:6931/runfunction.wasm:wasm-function[2429]:0xf887b
main@http://192.168.1.106:6931/runfunction.wasm:wasm-function[451]:0x15c90
Module._main@http://192.168.1.106:6931/qtloader.js line 443 > eval:14540:32
callMain@http://192.168.1.106:6931/qtloader.js line 443 > eval:15682:28
doRun@http://192.168.1.106:6931/qtloader.js line 443 > eval:15741:31
run/<@http://192.168.1.106:6931/qtloader.js line 443 > eval:15752:7