[llvm] SafeStack: Respect alloca addrspace (PR #112536)

[Vitaly Buka via llvm-commits]

vitalybuka wrote:

I suspect SafeStack require address space of UnsafeStackPtr and StackPtr is the same.

Maybe just fatal error if address space of PointerType::getUnqual != DL.getAllocaPtrType?

https://github.com/llvm/llvm-project/pull/112536