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

[Heejin Ahn via cfe-commits]

aheejin wrote:

@yamt Given that this PR is not large and we already went through it anyway, nevermind what I said about rebasing, and please use whatever method you are convenient with. But just FYI  you can do `git merge` to avoid rebasing (I'm not asking you to do it here; just in case you aren't aware)

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