[clang] [llvm] [ARM] Add support for Windows SEH (PR #184953)

[via llvm-commits]

gailium119 wrote:

iirc vcalls are also broken on windows arm32 target in llvm 12, dunno if it is fixed in latest version
And C++ exceptions are more tricky than seh

https://github.com/llvm/llvm-project/pull/184953