[llvm] [openmp] [openmp][WebAssembly] Allow openmp to compile and run under emscripten toolchain (PR #95169)

[Jaap Aarts via llvm-commits]

JAicewizard wrote:

@arsnyder16 I am working on getting this into emscripten, however when i run with this patch I get `undefined symbol '__kmp_unnamed_critical_addr'.`. It seems these are indeed never defined for `KMP_ARCH_WASM` as before.

This seems like an uncaught mistake?

https://github.com/llvm/llvm-project/pull/95169