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

[Heejin Ahn via llvm-commits]

aheejin wrote:

> > the JS invoke wrappers cannot return multivalue because JS doesn't support that
> 
> Doesn't it? I thought multivalue interacts with JS by having multivalue function called from JS return JS arrays of values.

Hmm, yeah, you're right. It's not an inherent limitation of JS but rather our invoke wrapper-specific issue... 

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