[llvm] [WinEH] Emit unreachable on malformed catchpad (PR #222181)

[Aaron Danen via llvm-commits]

aadanen wrote:

Ah. One issue is that so far I have been determining the expected properties of the catchpad arguments by looking at the assumptions made when using them. Since nobody uses Wasm_D I have no way to infer the properties that should be verified. For now I can just do nothing when detecting it and assume it is always valid. If we know it is the same as the other wasm personality let me know and I can treat them as equivalent.

https://github.com/llvm/llvm-project/pull/222181