[clang] clang: Forward exception_model flag for bitcode inputs (PR #146342)

[Martin Storsjö via cfe-commits]

mstorsjo wrote:

This broke building C++ modules for mingw targets. Repro:

`empty.cppm`:
```c++
export module empty;
```

```console
$ clang -target x86_64-windows-gnu -x c++-module empty.cppm -c -o empty.cppm.obj -std=gnu++23
error: invalid value 'seh' in '-exception-model=seh'
```

https://github.com/llvm/llvm-project/pull/146342