[clang] clang: Fix parsing of seh exception model (PR #146643)

[Martin Storsjö via cfe-commits]

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

Thanks, this looks good to me! I'd still wait a little bit in case a Clang maintainer has an opinion on it, but it seems to fix the issue for me.

https://github.com/llvm/llvm-project/pull/146643