[llvm] [WebAssembly] Add a threshold to RegStackify to avoid register spills at runtime (PR #97283)

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yolanda15 wrote:

> So in which case are deep stacks bad for performance and why? Reading @eqrion and @jakobkummerow's comments, it doesn't sound like deep stacks are necessarily bad. @jakobkummerow noted that it can be bad to have too many short-lived locals but it's not the case here right?

Sorry for the late response. I have created an issue to describe the problem at https://github.com/llvm/llvm-project/issues/98631. Hope it's more clear. 

Yes, I think its not the same case as noted by @jakobkummerow on too may short-lived locals. It should be a different issue.

https://github.com/llvm/llvm-project/pull/97283