strange segfault calling glTexImage2D with PROXY_TO_PTHREAD and disabled optimisation -O0

**Version of emscripten/emsdk:**
emcc (Emscripten gcc/clang-like replacement + linker emulating GNU ld) 4.0.5 (53b38d0c6f9fce1b62c55a8012bc6477f7a42711)
clang version 21.0.0git (https:/github.com/llvm/llvm-project 553da9634dc4bae215e6c850d2de3186d09f9da5)
Target: wasm32-unknown-emscripten

Simple test project in a gist

https://gist.github.com/xriss/66340cdb1dbe18d829b43e9489cd393c

Changing to -O1 fixes the issue...

I hit this in a bigger project and then broke it down into this to recreate the issue, I thought it might be something strange to do with GL_PACK/UNPACK_ALIGNMENT settings but that doesn't seem to be it.