[clang] [llvm] WebAssembly: Remove -wasm-enable-eh cl::opt in favor of -exception-model=wasm (PR #224313)

[Heejin Ahn via cfe-commits]

https://github.com/aheejin approved this pull request.

Thanks! This has to wait until https://github.com/emscripten-core/emscripten/pull/27739 lands to pass our autorollers.

https://github.com/llvm/llvm-project/pull/224313