[clang] [SSAF] Mark two failing tests as unsupported (PR #223976)

[Balázs Benics via cfe-commits]

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

Please mention thr failure output directly in the PR summary, the commit that introduced the failure.
Wait for green premerge checks before merging.

https://github.com/llvm/llvm-project/pull/223976