[clang] [llvm] [WinEH] Fix crash, object unwinding in the except block (PR #172287)

[via llvm-commits]

MuellerMP wrote:

@GkvJwa 
`The calculateSEHStateNumbers function currently does NOT know about C++ EH constructs like the emitted seh_scope_begin. We simply skip over it in the state numbering which causes the issue.`
=> Thus the correct refusal pattern would be a function with personality `__C_specific_handler` that contains `seh_scope_begin`. LLVM does not currently handle this circumstance correctly. And IMO it should not try to do so.

https://github.com/llvm/llvm-project/pull/172287