[llvm] [WebAssembly] Add RefTypeMem2Local pass (PR #81965)

[Heejin Ahn via llvm-commits]

aheejin wrote:

@pmatos Yes, replacing the mem2reg with this pass seems to work on all existing LLVM and Emscripten reference type tests. I am planning to upload the that, I mean the replacing, as a follow-up to this PR.

https://github.com/llvm/llvm-project/pull/81965