Uncaught RuntimeError: unreachable from worker

**Version of emscripten/emsdk:**
emcc (Emscripten gcc/clang-like replacement + linker emulating GNU ld) 3.1.32 (eab98adf462c39f3c31d348331c4830bcaa36949)
clang version 17.0.0 (https://github.com/llvm/llvm-project df82394e7a2d06506718cafa347bf7827c79fc4f)
Target: wasm32-unknown-emscripten
Thread model: posix

I am building [svt-av1](https://gitlab.com/AOMediaCodec/SVT-AV1) v1.4.1 for [ffmpeg](https://github.com/FFmpeg/FFmpeg) with emscripten 3.1.32. I managed to successfully compile to wasm, but during runtime (in browser worker), I am getting these exceptions:

 )

First I thought this might be related to large number of processes/workers being opened, however I can restrict the count to some reasonable ~20 which is tested safe with some other examples.

Here are my compilation flags, I think I am being generous with memory:

```
-s INITIAL_MEMORY=256mb
-s ALLOW_MEMORY_GROWTH=1
-s MAXIMUM_MEMORY=4gb
-s ENVIRONMENT=worker
-s PROXY_TO_PTHREAD=1
-s STACK_SIZE=10MB
-s DEFAULT_PTHREAD_STACK_SIZE=4MB
-pthread
```

...also `-msimd128` is being used.

At this point I am not sure this to which technology the error is related to (emscripten, webassembly, svtav1) but considering the error message (note attached screenshot) I will have hard time reporting error to svtav1 issue tracker and so decided to ask here first.

I would like to kindly ask the elders of the emscripten if this appears like something to be fixed on emscripten side?