[llvm] [WebAssembly] Add -wasm-use-legacy-eh option (PR #122158)

[Heejin Ahn via llvm-commits]

aheejin wrote:

> Sounds good to me. Could you also add documentation for this to the WebAssembly section of llvm/docs/ReleaseNotes.rst?

Done

https://github.com/llvm/llvm-project/pull/122158