[llvm] WebAssembly: Stop changing MCAsmInfo's ExceptionsType based on flags (PR #146343)

[Matt Arsenault via llvm-commits]

arsenm wrote:

>  and is not really related to this PR or my previous PR.

It's not, the main point is TargetOptions should not exist and everything in it should be migrated somewhere else 

https://github.com/llvm/llvm-project/pull/146343