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

[Sam Clegg via llvm-commits]

sbc100 wrote:

Is this good to land now?  @yamt do you have commit access or should @aheejin or myself land this?

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