[llvm] [WebAssembly] Don't return multivalue when Emscripten EH/SjLj is used (PR #86048)

[Heejin Ahn via llvm-commits]

aheejin wrote:

cc @TerrorJack in case you are interested. If you are using emscripten this may affect your results, but I don't think you are..?

https://github.com/llvm/llvm-project/pull/86048