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

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GkvJwa wrote:

> Ahh okay there is even more issues hidden here sadly: `__try`+`__finally` (`<PerformSEHFinally>`) uses `NormalAndEHCleanup` aswell and thus emits `seh.scope.begin` even though the state numbering algo ignores it. This makes fixing this very tricky. I might take a further look as well once christmas holidays have passed.

Yes, it's indeed difficult to solve this problem without processing through `Stmt`. Many concepts (such as determining whether a destructor exists within a `__try` or `__except` block) do not exist in `CodeGenFunction`.

Let's go on vacation first. Have a great holiday!

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