[clang] [llvm] SystemZ: Add support for __builtin_setjmp and __builtin_longjmp. (PR #119257)

[Ulrich Weigand via llvm-commits]

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

LGTM, let's try to merge again.

https://github.com/llvm/llvm-project/pull/119257