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

[Cheng Shao via llvm-commits]

TerrorJack wrote:

@aheejin Thanks for the ping! Our toolchain does not use emscripten sjlj mechanism fyi.

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