[clang] [llvm] [WebAssembly] Implement an alternative translation for -wasm-enable-sjlj (PR #84137)

[Sam Clegg via cfe-commits]

https://github.com/sbc100 commented:

Let me know if you want some help testing alsongside the emscripten side.

Alternatively myself or @aheejin could perform the emscripten tests.

https://github.com/llvm/llvm-project/pull/84137